Merge kroah.com:/home/greg/linux/BK/bleeding_edge-2.5

into kroah.com:/home/greg/linux/BK/gregkh-2.5

Documentation/DocBook/kernel-api.tmpl

@@ -299,6 +299,8 @@ KAO -->
     EHCI, OHCI, or UHCI.
     </para>
 !Edrivers/usb/core/hcd.c
+!Edrivers/usb/core/hcd-pci.c
+!Edrivers/usb/core/buffer.c
     </sect1>
 
   </chapter>

drivers/usb/core/Makefile

@@ -2,10 +2,10 @@
 # Makefile for USB Core files and filesystem
 #
 
-export-objs	:= usb.o hcd.o hcd-pci.o urb.o message.o file.o
+export-objs	:= usb.o hcd.o hcd-pci.o urb.o message.o file.o buffer.o
 
 usbcore-objs	:= usb.o usb-debug.o hub.o hcd.o urb.o message.o \
-			config.o file.o
+			config.o file.o buffer.o
 
 ifeq ($(CONFIG_PCI),y)
 	usbcore-objs	+= hcd-pci.o

drivers/usb/core/buffer.c

+/*
+ * DMA memory management for framework level HCD code (hc_driver)
+ *
+ * This implementation plugs in through generic "usb_bus" level methods,
+ * and works with real PCI, or when "pci device == null" makes sense.
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/version.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/pci.h>
+
+
+#ifdef CONFIG_USB_DEBUG
+	#define DEBUG
+#else
+	#undef DEBUG
+#endif
+
+#include <linux/usb.h>
+#include "hcd.h"
+
+
+/*
+ * DMA-Consistent Buffers
+ */
+
+/* FIXME tune these based on pool statistics ... */
+static const size_t	pool_max [HCD_BUFFER_POOLS] = {
+	32,
+	128,
+	512,
+	PAGE_SIZE / 2
+	/* bigger --> allocate pages */
+};
+
+
+/* SETUP primitives */
+
+/**
+ * hcd_buffer_create - initialize buffer pools
+ * @hcd: the bus whose buffer pools are to be initialized
+ *
+ * Call this as part of initializing a host controller that uses the pci dma
+ * memory allocators.  It initializes some pools of dma-consistent memory that
+ * will be shared by all drivers using that controller, or returns a negative
+ * errno value on error.
+ *
+ * Call hcd_buffer_destroy() to clean up after using those pools.
+ */
+int hcd_buffer_create (struct usb_hcd *hcd)
+{
+	char		name [16];
+	int 		i, size;
+
+	for (i = 0; i < HCD_BUFFER_POOLS; i++) { 
+		if (!(size = pool_max [i]))
+			continue;
+		snprintf (name, sizeof name, "buffer-%d", size);
+		hcd->pool [i] = pci_pool_create (name, hcd->pdev,
+				size, size, 0, SLAB_KERNEL);
+		if (!hcd->pool [i]) {
+			hcd_buffer_destroy (hcd);
+			return -ENOMEM;
+		}
+	}
+	return 0;
+}
+EXPORT_SYMBOL (hcd_buffer_create);
+
+
+/**
+ * hcd_buffer_destroy - deallocate buffer pools
+ * @hcd: the bus whose buffer pools are to be destroyed
+ *
+ * This frees the buffer pools created by hcd_buffer_create().
+ */
+void hcd_buffer_destroy (struct usb_hcd *hcd)
+{
+	int		i;
+
+	for (i = 0; i < HCD_BUFFER_POOLS; i++) { 
+		struct pci_pool		*pool = hcd->pool [i];
+		if (pool) {
+			pci_pool_destroy (pool);
+			hcd->pool [i] = 0;
+		}
+	}
+}
+EXPORT_SYMBOL (hcd_buffer_destroy);
+
+
+/* sometimes alloc/free could use kmalloc with SLAB_DMA, for
+ * better sharing and to leverage mm/slab.c intelligence.
+ */
+
+void *hcd_buffer_alloc (
+	struct usb_bus 		*bus,
+	size_t			size,
+	int			mem_flags,
+	dma_addr_t		*dma
+)
+{
+	struct usb_hcd		*hcd = bus->hcpriv;
+	int 			i;
+
+	for (i = 0; i < HCD_BUFFER_POOLS; i++) {
+		if (size <= pool_max [i])
+			return pci_pool_alloc (hcd->pool [i], mem_flags, dma);
+	}
+	return pci_alloc_consistent (hcd->pdev, size, dma);
+}
+
+void hcd_buffer_free (
+	struct usb_bus 		*bus,
+	size_t			size,
+	void 			*addr,
+	dma_addr_t		dma
+)
+{
+	struct usb_hcd		*hcd = bus->hcpriv;
+	int 			i;
+
+	for (i = 0; i < HCD_BUFFER_POOLS; i++) {
+		if (size <= pool_max [i]) {
+			pci_pool_free (hcd->pool [i], addr, dma);
+			return;
+		}
+	}
+	pci_free_consistent (hcd->pdev, size, addr, dma);
+}
+
+
+/*
+ * DMA-Mappings for arbitrary memory buffers
+ */
+
+int hcd_buffer_map (
+	struct usb_bus	*bus,
+	void		*addr,
+	dma_addr_t	*dma,
+	size_t		size,
+	int		direction
+) {
+	struct usb_hcd	*hcd = bus->hcpriv;
+
+	// FIXME pci_map_single() has no standard failure mode!
+	*dma = pci_map_single (hcd->pdev, addr, size,
+			(direction == USB_DIR_IN)
+				? PCI_DMA_FROMDEVICE
+				: PCI_DMA_TODEVICE);
+	return 0;
+}
+
+void hcd_buffer_dmasync (
+	struct usb_bus	*bus,
+	dma_addr_t	dma,
+	size_t		size,
+	int		direction
+) {
+	struct usb_hcd *hcd = bus->hcpriv;
+
+	pci_dma_sync_single (hcd->pdev, dma, size,
+			(direction == USB_DIR_IN)
+				? PCI_DMA_FROMDEVICE
+				: PCI_DMA_TODEVICE);
+}
+
+void hcd_buffer_unmap (
+	struct usb_bus	*bus,
+	dma_addr_t	dma,
+	size_t		size,
+	int		direction
+) {
+	struct usb_hcd *hcd = bus->hcpriv;
+
+	pci_unmap_single (hcd->pdev, dma, size,
+			(direction == USB_DIR_IN)
+				? PCI_DMA_FROMDEVICE
+				: PCI_DMA_TODEVICE);
+}
+
+
+// FIXME DMA-Mappings for struct scatterlist

drivers/usb/core/hcd-pci.c

@@ -130,10 +130,19 @@ int usb_hcd_pci_probe (struct pci_dev *dev, const struct pci_device_id *id)
 			return retval;
 		}
 	}
-	pci_set_drvdata(dev, hcd);
+	pci_set_drvdata (dev, hcd);
 	hcd->driver = driver;
 	hcd->description = driver->description;
 	hcd->pdev = dev;
+	hcd->self.bus_name = dev->slot_name;
+	hcd->product_desc = dev->name;
+
+	if ((retval = hcd_buffer_create (hcd)) != 0) {
+clean_3:
+		driver->hcd_free (hcd);
+		goto clean_2;
+	}
+
 	info ("%s @ %s, %s", hcd->description,  dev->slot_name, dev->name);
 
 	pci_read_config_byte (dev, PCI_LATENCY_TIMER, &latency);
@@ -154,8 +163,7 @@ int usb_hcd_pci_probe (struct pci_dev *dev, const struct pci_device_id *id)
 			!= 0) {
 		err ("request interrupt %s failed", bufp);
 		retval = -EBUSY;
-		driver->hcd_free (hcd);
-		goto clean_2;
+		goto clean_3;
 	}
 	hcd->irq = dev->irq;
 
@@ -168,8 +176,6 @@ int usb_hcd_pci_probe (struct pci_dev *dev, const struct pci_device_id *id)
 	usb_bus_init (&hcd->self);
 	hcd->self.op = &usb_hcd_operations;
 	hcd->self.hcpriv = (void *) hcd;
-	hcd->self.bus_name = dev->slot_name;
-	hcd->product_desc = dev->name;
 
 	INIT_LIST_HEAD (&hcd->dev_list);
 
@@ -216,6 +222,7 @@ void usb_hcd_pci_remove (struct pci_dev *dev)
 	usb_disconnect (&hub);
 
 	hcd->driver->stop (hcd);
+	hcd_buffer_destroy (hcd);
 	hcd->state = USB_STATE_HALT;
 
 	free_irq (hcd->irq, hcd);

drivers/usb/core/hcd.c

@@ -454,7 +454,6 @@ static int rh_status_urb (struct usb_hcd *hcd, struct urb *urb)
 	/* rh_timer protected by hcd_data_lock */
 	if (timer_pending (&hcd->rh_timer)
 			|| urb->status != -EINPROGRESS
-			|| !HCD_IS_RUNNING (hcd->state)
 			|| urb->transfer_buffer_length < len) {
 		dbg ("not queuing status urb, stat %d", urb->status);
 		return -EINVAL;
@@ -508,8 +507,12 @@ static void rh_report_status (unsigned long ptr)
 				BUG ();
 			}
 			spin_unlock_irqrestore (&hcd_data_lock, flags);
-		} else
+		} else {
 			spin_unlock_irqrestore (&urb->lock, flags);
+			spin_lock_irqsave (&hcd_data_lock, flags);
+			rh_status_urb (hcd, urb);
+			spin_unlock_irqrestore (&hcd_data_lock, flags);
+		}
 	} else {
 		/* this urb's been unlinked */
 		urb->hcpriv = 0;
@@ -1245,6 +1248,11 @@ struct usb_operations usb_hcd_operations = {
 	.submit_urb =		hcd_submit_urb,
 	.unlink_urb =		hcd_unlink_urb,
 	.deallocate =		hcd_free_dev,
+	.buffer_alloc =		hcd_buffer_alloc,
+	.buffer_free =		hcd_buffer_free,
+	.buffer_map =		hcd_buffer_map,
+	.buffer_dmasync =	hcd_buffer_dmasync,
+	.buffer_unmap =		hcd_buffer_unmap,
 };
 EXPORT_SYMBOL (usb_hcd_operations);
 

drivers/usb/core/hcd.h

@@ -58,6 +58,9 @@ struct usb_hcd {	/* usb_bus.hcpriv points to this */
 	atomic_t		resume_count;	/* multiple resumes issue */
 #endif
 
+#define HCD_BUFFER_POOLS	4
+	struct pci_pool		*pool [HCD_BUFFER_POOLS];
+
 	int			state;
 #	define	__ACTIVE		0x01
 #	define	__SLEEPY		0x02
@@ -109,6 +112,25 @@ struct usb_operations {
 	int (*get_frame_number) (struct usb_device *usb_dev);
 	int (*submit_urb) (struct urb *urb, int mem_flags);
 	int (*unlink_urb) (struct urb *urb);
+
+	/* allocate dma-consistent buffer for URB_DMA_NOMAPPING */
+	void *(*buffer_alloc)(struct usb_bus *bus, size_t size,
+			int mem_flags,
+			dma_addr_t *dma);
+	void (*buffer_free)(struct usb_bus *bus, size_t size,
+			void *addr, dma_addr_t dma);
+
+	int (*buffer_map) (struct usb_bus *bus,
+		void *addr, dma_addr_t *dma,
+		size_t size, int direction);
+	void (*buffer_dmasync) (struct usb_bus *bus,
+		dma_addr_t dma,
+		size_t size, int direction);
+	void (*buffer_unmap) (struct usb_bus *bus,
+		dma_addr_t dma,
+		size_t size, int direction);
+
+	// FIXME  also: buffer_sg_map (), buffer_sg_unmap ()
 };
 
 /* each driver provides one of these, and hardware init support */
@@ -181,6 +203,25 @@ extern int usb_hcd_pci_resume (struct pci_dev *dev);
 
 #endif /* CONFIG_PCI */
 
+/* pci-ish (pdev null is ok) buffer alloc/mapping support */
+int hcd_buffer_create (struct usb_hcd *hcd);
+void hcd_buffer_destroy (struct usb_hcd *hcd);
+
+void *hcd_buffer_alloc (struct usb_bus *bus, size_t size,
+	int mem_flags, dma_addr_t *dma);
+void hcd_buffer_free (struct usb_bus *bus, size_t size,
+	void *addr, dma_addr_t dma);
+
+int hcd_buffer_map (struct usb_bus *bus,
+	void *addr, dma_addr_t *dma,
+	size_t size, int direction);
+void hcd_buffer_dmasync (struct usb_bus *bus,
+	dma_addr_t dma,
+	size_t size, int direction);
+void hcd_buffer_unmap (struct usb_bus *bus,
+	dma_addr_t dma,
+	size_t size, int direction);
+
 /* generic bus glue, needed for host controllers that don't use PCI */
 extern struct usb_operations usb_hcd_operations;
 extern void usb_hcd_irq (int irq, void *__hcd, struct pt_regs *r);

drivers/usb/core/usb.c

@@ -864,8 +864,10 @@ static ssize_t show_product (struct device *dev, char *buf, size_t count, loff_t
 	udev = to_usb_device (dev);
 
 	len = usb_string(udev, udev->descriptor.iProduct, buf, PAGE_SIZE);
+	if (len < 0)
+		return 0;
 	buf[len] = '\n';
-	buf[len+1] = 0x00;
+	buf[len+1] = 0;
 	return len+1;
 }
 static DEVICE_ATTR(product,"product",S_IRUGO,show_product,NULL);
@@ -882,8 +884,10 @@ show_manufacturer (struct device *dev, char *buf, size_t count, loff_t off)
 	udev = to_usb_device (dev);
 
 	len = usb_string(udev, udev->descriptor.iManufacturer, buf, PAGE_SIZE);
+	if (len < 0)
+		return 0;
 	buf[len] = '\n';
-	buf[len+1] = 0x00;
+	buf[len+1] = 0;
 	return len+1;
 }
 static DEVICE_ATTR(manufacturer,"manufacturer",S_IRUGO,show_manufacturer,NULL);
@@ -900,8 +904,10 @@ show_serial (struct device *dev, char *buf, size_t count, loff_t off)
 	udev = to_usb_device (dev);
 
 	len = usb_string(udev, udev->descriptor.iSerialNumber, buf, PAGE_SIZE);
+	if (len < 0)
+		return 0;
 	buf[len] = '\n';
-	buf[len+1] = 0x00;
+	buf[len+1] = 0;
 	return len+1;
 }
 static DEVICE_ATTR(serial,"serial",S_IRUGO,show_serial,NULL);
@@ -918,7 +924,7 @@ static void usb_find_drivers(struct usb_device *dev)
 	unsigned claimed = 0;
 
 	/* FIXME should get called for each new configuration not just the
-	 * first one for a device. switching configs (or altesettings) should
+	 * first one for a device. switching configs (or altsettings) should
 	 * undo driverfs and HCD state for the previous interfaces.
 	 */
 	for (ifnum = 0; ifnum < dev->actconfig->bNumInterfaces; ifnum++) {
@@ -1455,6 +1461,152 @@ int usb_new_device(struct usb_device *dev)
 }
 
 
+/**
+ * usb_buffer_alloc - allocate dma-consistent buffer for URB_NO_DMA_MAP
+ * @dev: device the buffer will be used with
+ * @size: requested buffer size
+ * @mem_flags: affect whether allocation may block
+ * @dma: used to return DMA address of buffer
+ *
+ * Return value is either null (indicating no buffer could be allocated), or
+ * the cpu-space pointer to a buffer that may be used to perform DMA to the
+ * specified device.  Such cpu-space buffers are returned along with the DMA
+ * address (through the pointer provided).
+ *
+ * These buffers are used with URB_NO_DMA_MAP set in urb->transfer_flags to
+ * avoid behaviors like using "DMA bounce buffers", or tying down I/O mapping
+ * hardware for long idle periods.  The implementation varies between
+ * platforms, depending on details of how DMA will work to this device.
+ *
+ * When the buffer is no longer used, free it with usb_buffer_free().
+ */
+void *usb_buffer_alloc (
+	struct usb_device *dev,
+	size_t size,
+	int mem_flags,
+	dma_addr_t *dma
+)
+{
+	if (!dev || !dev->bus || !dev->bus->op || !dev->bus->op->buffer_alloc)
+		return 0;
+	return dev->bus->op->buffer_alloc (dev->bus, size, mem_flags, dma);
+}
+
+/**
+ * usb_buffer_free - free memory allocated with usb_buffer_alloc()
+ * @dev: device the buffer was used with
+ * @size: requested buffer size
+ * @addr: CPU address of buffer
+ * @dma: DMA address of buffer
+ *
+ * This reclaims an I/O buffer, letting it be reused.  The memory must have
+ * been allocated using usb_buffer_alloc(), and the parameters must match
+ * those provided in that allocation request. 
+ */
+void usb_buffer_free (
+	struct usb_device *dev,
+	size_t size,
+	void *addr,
+	dma_addr_t dma
+)
+{
+	if (!dev || !dev->bus || !dev->bus->op || !dev->bus->op->buffer_free)
+	    	return;
+	dev->bus->op->buffer_free (dev->bus, size, addr, dma);
+}
+
+/**
+ * usb_buffer_map - create DMA mapping(s) for an urb
+ * @urb: urb whose transfer_buffer will be mapped
+ *
+ * Return value is either null (indicating no buffer could be mapped), or
+ * the parameter.  URB_NO_DMA_MAP is added to urb->transfer_flags if the
+ * operation succeeds.
+ *
+ * This call would normally be used for an urb which is reused, perhaps
+ * as the target of a large periodic transfer, with usb_buffer_dmasync()
+ * calls to synchronize memory and dma state.  It may not be used for
+ * control requests.
+ *
+ * Reverse the effect of this call with usb_buffer_unmap().
+ */
+struct urb *usb_buffer_map (struct urb *urb)
+{
+	struct usb_bus		*bus;
+	struct usb_operations	*op;
+
+	if (!urb
+			|| usb_pipecontrol (urb->pipe)
+			|| !urb->dev
+			|| !(bus = urb->dev->bus)
+			|| !(op = bus->op)
+			|| !op->buffer_map)
+		return 0;
+
+	if (op->buffer_map (bus,
+			urb->transfer_buffer,
+			&urb->transfer_dma,
+			urb->transfer_buffer_length,
+			usb_pipein (urb->pipe)
+				? USB_DIR_IN
+				: USB_DIR_OUT))
+		return 0;
+	urb->transfer_flags |= URB_NO_DMA_MAP;
+	return urb;
+}
+
+/**
+ * usb_buffer_dmasync - synchronize DMA and CPU view of buffer(s)
+ * @urb: urb whose transfer_buffer will be synchronized
+ */
+void usb_buffer_dmasync (struct urb *urb)
+{
+	struct usb_bus		*bus;
+	struct usb_operations	*op;
+
+	if (!urb
+			|| !(urb->transfer_flags & URB_NO_DMA_MAP)
+			|| !urb->dev
+			|| !(bus = urb->dev->bus)
+			|| !(op = bus->op)
+			|| !op->buffer_dmasync)
+		return;
+
+	op->buffer_dmasync (bus,
+			urb->transfer_dma,
+			urb->transfer_buffer_length,
+			usb_pipein (urb->pipe)
+				? USB_DIR_IN
+				: USB_DIR_OUT);
+}
+
+/**
+ * usb_buffer_unmap - free DMA mapping(s) for an urb
+ * @urb: urb whose transfer_buffer will be unmapped
+ *
+ * Reverses the effect of usb_buffer_map().
+ */
+void usb_buffer_unmap (struct urb *urb)
+{
+	struct usb_bus		*bus;
+	struct usb_operations	*op;
+
+	if (!urb
+			|| !(urb->transfer_flags & URB_NO_DMA_MAP)
+			|| !urb->dev
+			|| !(bus = urb->dev->bus)
+			|| !(op = bus->op)
+			|| !op->buffer_unmap)
+		return;
+
+	op->buffer_unmap (bus,
+			urb->transfer_dma,
+			urb->transfer_buffer_length,
+			usb_pipein (urb->pipe)
+				? USB_DIR_IN
+				: USB_DIR_OUT);
+}
+
 #ifdef CONFIG_PROC_FS
 struct list_head *usb_driver_get_list(void)
 {
@@ -1534,4 +1686,11 @@ EXPORT_SYMBOL(__usb_get_extra_descriptor);
 
 EXPORT_SYMBOL(usb_get_current_frame_number);
 
+EXPORT_SYMBOL (usb_buffer_alloc);
+EXPORT_SYMBOL (usb_buffer_free);
+
+EXPORT_SYMBOL (usb_buffer_map);
+EXPORT_SYMBOL (usb_buffer_dmasync);
+EXPORT_SYMBOL (usb_buffer_unmap);
+
 MODULE_LICENSE("GPL");

drivers/usb/host/ehci-dbg.c

 /*
- * Copyright (c) 2001 by David Brownell
+ * Copyright (c) 2001-2002 by David Brownell
  * 
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License as published by the
@@ -175,3 +175,215 @@ dbg_qh (char *label, struct ehci_hcd *ehci, struct ehci_qh *qh) {}
 		(status & PORT_CONNECT) ? " CONNECT" : "" \
 	    )
 
+#ifdef DEBUG
+
+#define speed_char(info1) ({ char tmp; \
+		switch (info1 & (3 << 12)) { \
+		case 0 << 12: tmp = 'f'; break; \
+		case 1 << 12: tmp = 'l'; break; \
+		case 2 << 12: tmp = 'h'; break; \
+		default: tmp = '?'; break; \
+		}; tmp; })
+
+static ssize_t
+show_async (struct device *dev, char *buf, size_t count, loff_t off)
+{
+	struct pci_dev		*pdev;
+	struct ehci_hcd		*ehci;
+	unsigned long		flags;
+	unsigned		temp, size;
+	char			*next;
+	struct ehci_qh		*qh;
+
+	if (off != 0)
+		return 0;
+
+	pdev = container_of (dev, struct pci_dev, dev);
+	ehci = container_of (pci_get_drvdata (pdev), struct ehci_hcd, hcd);
+	next = buf;
+	size = count;
+
+	/* dumps a snapshot of the async schedule.
+	 * usually empty except for long-term bulk reads, or head.
+	 * one QH per line, and TDs we know about
+	 */
+	spin_lock_irqsave (&ehci->lock, flags);
+	if (ehci->async) {
+		qh = ehci->async;
+		do {
+			u32			scratch;
+			struct list_head	*entry;
+			struct ehci_qtd		*td;
+
+			scratch = cpu_to_le32p (&qh->hw_info1);
+			temp = snprintf (next, size, "qh %p dev%d %cs ep%d",
+					qh, scratch & 0x007f,
+					speed_char (scratch),
+					(scratch >> 8) & 0x000f);
+			size -= temp;
+			next += temp;
+
+			list_for_each (entry, &qh->qtd_list) {
+				td = list_entry (entry, struct ehci_qtd,
+						qtd_list);
+				scratch = cpu_to_le32p (&td->hw_token);
+				temp = snprintf (next, size,
+						", td %p len=%d %s",
+						td, scratch >> 16,
+						({ char *tmp;
+						 switch ((scratch>>8)&0x03) {
+						 case 0: tmp = "out"; break;
+						 case 1: tmp = "in"; break;
+						 case 2: tmp = "setup"; break;
+						 default: tmp = "?"; break;
+						 } tmp;})
+						);
+				size -= temp;
+				next += temp;
+			}
+
+			temp = snprintf (next, size, "\n");
+			size -= temp;
+			next += temp;
+
+		} while ((qh = qh->qh_next.qh) != ehci->async);
+	}
+	spin_unlock_irqrestore (&ehci->lock, flags);
+
+	return count - size;
+}
+static DEVICE_ATTR (async, "sched-async", S_IRUSR, show_async, NULL);
+
+#define DBG_SCHED_LIMIT 64
+
+static ssize_t
+show_periodic (struct device *dev, char *buf, size_t count, loff_t off)
+{
+	struct pci_dev		*pdev;
+	struct ehci_hcd		*ehci;
+	unsigned long		flags;
+	union ehci_shadow	p, *seen;
+	unsigned		temp, size, seen_count;
+	char			*next;
+	unsigned		i, tag;
+
+	if (off != 0)
+		return 0;
+	if (!(seen = kmalloc (DBG_SCHED_LIMIT * sizeof *seen, SLAB_ATOMIC)))
+		return 0;
+	seen_count = 0;
+
+	pdev = container_of (dev, struct pci_dev, dev);
+	ehci = container_of (pci_get_drvdata (pdev), struct ehci_hcd, hcd);
+	next = buf;
+	size = count;
+
+	temp = snprintf (next, size, "size = %d\n", ehci->periodic_size);
+	size -= temp;
+	next += temp;
+
+	/* dump a snapshot of the periodic schedule.
+	 * iso changes, interrupt usually doesn't.
+	 */
+	spin_lock_irqsave (&ehci->lock, flags);
+	for (i = 0; i < ehci->periodic_size; i++) {
+		p = ehci->pshadow [i];
+		if (!p.ptr)
+			continue;
+		tag = Q_NEXT_TYPE (ehci->periodic [i]);
+
+		temp = snprintf (next, size, "%4d: ", i);
+		size -= temp;
+		next += temp;
+
+		do {
+			switch (tag) {
+			case Q_TYPE_QH:
+				temp = snprintf (next, size, " intr-%d %p",
+						p.qh->period, p.qh);
+				size -= temp;
+				next += temp;
+				for (temp = 0; temp < seen_count; temp++) {
+					if (seen [temp].ptr == p.ptr)
+						break;
+				}
+				/* show more info the first time around */
+				if (temp == seen_count) {
+					u32	scratch = cpu_to_le32p (
+							&p.qh->hw_info1);
+
+					temp = snprintf (next, size,
+						" (%cs dev%d ep%d)",
+						speed_char (scratch),
+						scratch & 0x007f,
+						(scratch >> 8) & 0x000f);
+
+					/* FIXME TDs too */
+
+					if (seen_count < DBG_SCHED_LIMIT)
+						seen [seen_count++].qh = p.qh;
+				} else
+					temp = 0;
+				tag = Q_NEXT_TYPE (p.qh->hw_next);
+				p = p.qh->qh_next;
+				break;
+			case Q_TYPE_FSTN:
+				temp = snprintf (next, size,
+					" fstn-%8x/%p", p.fstn->hw_prev,
+					p.fstn);
+				tag = Q_NEXT_TYPE (p.fstn->hw_next);
+				p = p.fstn->fstn_next;
+				break;
+			case Q_TYPE_ITD:
+				temp = snprintf (next, size,
+					" itd/%p", p.itd);
+				tag = Q_NEXT_TYPE (p.itd->hw_next);
+				p = p.itd->itd_next;
+				break;
+			case Q_TYPE_SITD:
+				temp = snprintf (next, size,
+					" sitd/%p", p.sitd);
+				tag = Q_NEXT_TYPE (p.sitd->hw_next);
+				p = p.sitd->sitd_next;
+				break;
+			}
+			size -= temp;
+			next += temp;
+		} while (p.ptr);
+
+		temp = snprintf (next, size, "\n");
+		size -= temp;
+		next += temp;
+	}
+	spin_unlock_irqrestore (&ehci->lock, flags);
+	kfree (seen);
+
+	return count - size;
+}
+static DEVICE_ATTR (periodic, "sched-periodic", S_IRUSR, show_periodic, NULL);
+
+#undef DBG_SCHED_LIMIT
+
+static inline void create_debug_files (struct ehci_hcd *bus)
+{
+	device_create_file (&bus->hcd.pdev->dev, &dev_attr_async);
+	device_create_file (&bus->hcd.pdev->dev, &dev_attr_periodic);
+}
+
+static inline void remove_debug_files (struct ehci_hcd *bus)
+{
+	device_remove_file (&bus->hcd.pdev->dev, &dev_attr_async);
+	device_remove_file (&bus->hcd.pdev->dev, &dev_attr_periodic);
+}
+
+#else /* DEBUG */
+
+static inline void create_debug_files (struct ehci_hcd *bus)
+{
+}
+
+static inline void remove_debug_files (struct ehci_hcd *bus)
+{
+}
+
+#endif /* DEBUG */

drivers/usb/host/ehci-hcd.c

@@ -65,6 +65,8 @@
  *
  * HISTORY:
  *
+ * 2002-08-06	Handling for bulk and interrupt transfers is mostly shared;
+ *	only scheduling is different, no arbitrary limitations.
  * 2002-07-25	Sanity check PCI reads, mostly for better cardbus support,
  * 	clean up HC run state handshaking.
  * 2002-05-24	Preliminary FS/LS interrupts, using scheduling shortcuts
@@ -85,7 +87,7 @@
  * 2001-June	Works with usb-storage and NEC EHCI on 2.4
  */
 
-#define DRIVER_VERSION "2002-Jul-25"
+#define DRIVER_VERSION "2002-Aug-06"
 #define DRIVER_AUTHOR "David Brownell"
 #define DRIVER_DESC "USB 2.0 'Enhanced' Host Controller (EHCI) Driver"
 
@@ -93,6 +95,8 @@
 // #define EHCI_VERBOSE_DEBUG
 // #define have_split_iso
 
+#define INTR_AUTOMAGIC		/* to be removed later in 2.5 */
+
 /* magic numbers that can affect system performance */
 #define	EHCI_TUNE_CERR		3	/* 0-3 qtd retries; 0 == don't stop */
 #define	EHCI_TUNE_RL_HS		0	/* nak throttle; see 4.9 */
@@ -376,6 +380,8 @@ static int ehci_start (struct usb_hcd *hcd)
 		return -ENOMEM;
 	}
 
+	create_debug_files (ehci);
+
 	/*
 	 * Start, enabling full USB 2.0 functionality ... usb 1.1 devices
 	 * are explicitly handed to companion controller(s), so no TT is
@@ -429,6 +435,8 @@ static void ehci_stop (struct usb_hcd *hcd)
 		ehci_ready (ehci);
 	ehci_reset (ehci);
 
+	remove_debug_files (ehci);
+
 	/* root hub is shut down separately (first, when possible) */
 	tasklet_disable (&ehci->tasklet);
 	ehci_tasklet ((unsigned long) ehci);
@@ -614,7 +622,8 @@ static void ehci_irq (struct usb_hcd *hcd)
  *
  * hcd-specific init for hcpriv hasn't been done yet
  *
- * NOTE:  EHCI queues control and bulk requests transparently, like OHCI.
+ * NOTE:  control, bulk, and interrupt share the same code to append TDs
+ * to a (possibly active) QH, and the same QH scanning code.
  */
 static int ehci_urb_enqueue (
 	struct usb_hcd	*hcd,
@@ -626,10 +635,11 @@ static int ehci_urb_enqueue (
 
 	urb->transfer_flags &= ~EHCI_STATE_UNLINK;
 	INIT_LIST_HEAD (&qtd_list);
-	switch (usb_pipetype (urb->pipe)) {
 
-	case PIPE_CONTROL:
-	case PIPE_BULK:
+	switch (usb_pipetype (urb->pipe)) {
+	// case PIPE_CONTROL:
+	// case PIPE_BULK:
+	default:
 		if (!qh_urb_transaction (ehci, urb, &qtd_list, mem_flags))
 			return -ENOMEM;
 		return submit_async (ehci, urb, &qtd_list, mem_flags);
@@ -649,9 +659,6 @@ static int ehci_urb_enqueue (
 		dbg ("no split iso support yet");
 		return -ENOSYS;
 #endif /* have_split_iso */
-
-	default:	/* can't happen */
-		return -ENOSYS;
 	}
 }
 
@@ -665,15 +672,16 @@ static int ehci_urb_dequeue (struct usb_hcd *hcd, struct urb *urb)
 	struct ehci_qh		*qh = (struct ehci_qh *) urb->hcpriv;
 	unsigned long		flags;
 
-	dbg ("%s urb_dequeue %p qh state %d",
-		hcd->self.bus_name, urb, qh->qh_state);
+	dbg ("%s urb_dequeue %p qh %p state %d",
+		hcd->self.bus_name, urb, qh, qh->qh_state);
 
 	switch (usb_pipetype (urb->pipe)) {
-	case PIPE_CONTROL:
-	case PIPE_BULK:
+	// case PIPE_CONTROL:
+	// case PIPE_BULK:
+	default:
 		spin_lock_irqsave (&ehci->lock, flags);
 		if (ehci->reclaim) {
-dbg ("dq: reclaim busy, %s", RUN_CONTEXT);
+			dbg ("dq: reclaim busy, %s", RUN_CONTEXT);
 			if (in_interrupt ()) {
 				spin_unlock_irqrestore (&ehci->lock, flags);
 				return -EAGAIN;
@@ -683,28 +691,43 @@ dbg ("dq: reclaim busy, %s", RUN_CONTEXT);
 					&& ehci->hcd.state != USB_STATE_HALT
 					) {
 				spin_unlock_irqrestore (&ehci->lock, flags);
-// yeech ... this could spin for up to two frames!
-dbg ("wait for dequeue: state %d, reclaim %p, hcd state %d",
-    qh->qh_state, ehci->reclaim, ehci->hcd.state
-);
-				udelay (100);
+				/* let pending unlinks complete */
+				wait_ms (1);
 				spin_lock_irqsave (&ehci->lock, flags);
 			}
 		}
 		if (qh->qh_state == QH_STATE_LINKED)
 			start_unlink_async (ehci, qh);
 		spin_unlock_irqrestore (&ehci->lock, flags);
-		return 0;
+		break;
 
 	case PIPE_INTERRUPT:
-		intr_deschedule (ehci, urb->start_frame, qh,
-			(urb->dev->speed == USB_SPEED_HIGH)
-			    ? urb->interval
-			    : (urb->interval << 3));
-		if (ehci->hcd.state == USB_STATE_HALT)
-			urb->status = -ESHUTDOWN;
-		qh_completions (ehci, qh, 1);
-		return 0;
+		if (qh->qh_state == QH_STATE_LINKED) {
+			/* messy, can spin or block a microframe ... */
+			intr_deschedule (ehci, qh, 1);
+			/* qh_state == IDLE */
+		}
+		qh_completions (ehci, qh);
+
+		/* reschedule QH iff another request is queued */
+		if (!list_empty (&qh->qtd_list)
+				&& HCD_IS_RUNNING (ehci->hcd.state)) {
+			int status;
+
+			spin_lock_irqsave (&ehci->lock, flags);
+			status = qh_schedule (ehci, qh);
+			spin_unlock_irqrestore (&ehci->lock, flags);
+
+			if (status != 0) {
+				// shouldn't happen often, but ...
+				// FIXME kill those tds' urbs
+				err ("can't reschedule qh %p, err %d",
+					qh, status);
+			}
+			return status;
+		}
+
+		break;
 
 	case PIPE_ISOCHRONOUS:
 		// itd or sitd ...
@@ -712,9 +735,9 @@ dbg ("wait for dequeue: state %d, reclaim %p, hcd state %d",
 		// wait till next completion, do it then.
 		// completion irqs can wait up to 1024 msec,
 		urb->transfer_flags |= EHCI_STATE_UNLINK;
-		return 0;
+		break;
 	}
-	return -EINVAL;
+	return 0;
 }
 
 /*-------------------------------------------------------------------------*/
@@ -728,6 +751,7 @@ static void ehci_free_config (struct usb_hcd *hcd, struct usb_device *udev)
 	int			i;
 	unsigned long		flags;
 
+	/* ASSERT:  no requests/urbs are still linked (so no TDs) */
 	/* ASSERT:  nobody can be submitting urbs for this any more */
 
 	dbg ("%s: free_config devnum %d", hcd->self.bus_name, udev->devnum);
@@ -736,34 +760,57 @@ static void ehci_free_config (struct usb_hcd *hcd, struct usb_device *udev)
 	for (i = 0; i < 32; i++) {
 		if (dev->ep [i]) {
 			struct ehci_qh		*qh;
+			char			*why;
 
 			/* dev->ep never has ITDs or SITDs */
 			qh = (struct ehci_qh *) dev->ep [i];
-			vdbg ("free_config, ep 0x%02x qh %p", i, qh);
-			if (!list_empty (&qh->qtd_list)) {
-				dbg ("ep 0x%02x qh %p not empty!", i, qh);
+
+			/* detect/report non-recoverable errors */
+			if (in_interrupt ()) 
+				why = "disconnect() didn't";
+			else if ((qh->hw_info2 & cpu_to_le32 (0xffff)) != 0
+					&& qh->qh_state != QH_STATE_IDLE)
+				why = "(active periodic)";
+			else
+				why = 0;
+			if (why) {
+				err ("dev %s-%s ep %d-%s error: %s",
+					hcd->self.bus_name, udev->devpath,
+					i & 0xf, (i & 0x10) ? "IN" : "OUT",
+					why);
 				BUG ();
 			}
+
 			dev->ep [i] = 0;
+			if (qh->qh_state == QH_STATE_IDLE)
+				goto idle;
+			dbg ("free_config, async ep 0x%02x qh %p", i, qh);
 
-			/* wait_ms() won't spin here -- we're a thread */
+			/* scan_async() empties the ring as it does its work,
+			 * using IAA, but doesn't (yet?) turn it off.  if it
+			 * doesn't empty this qh, likely it's the last entry.
+			 */
 			while (qh->qh_state == QH_STATE_LINKED
 					&& ehci->reclaim
 					&& ehci->hcd.state != USB_STATE_HALT
 					) {
 				spin_unlock_irqrestore (&ehci->lock, flags);
+				/* wait_ms() won't spin, we're a thread;
+				 * and we know IRQ+tasklet can progress
+				 */
 				wait_ms (1);
 				spin_lock_irqsave (&ehci->lock, flags);
 			}
-			if (qh->qh_state == QH_STATE_LINKED) {
+			if (qh->qh_state == QH_STATE_LINKED)
 				start_unlink_async (ehci, qh);
-				while (qh->qh_state != QH_STATE_IDLE) {
+			while (qh->qh_state != QH_STATE_IDLE
+					&& ehci->hcd.state != USB_STATE_HALT) {
 				spin_unlock_irqrestore (&ehci->lock,
 					flags);
 				wait_ms (1);
 				spin_lock_irqsave (&ehci->lock, flags);
 			}
-			}
+idle:
 			qh_put (ehci, qh);
 		}
 	}

drivers/usb/host/ehci-q.c

@@ -47,9 +47,11 @@ static int
 qtd_fill (struct ehci_qtd *qtd, dma_addr_t buf, size_t len, int token)
 {
 	int	i, count;
+	u64	addr = buf;
 
 	/* one buffer entry per 4K ... first might be short or unaligned */
-	qtd->hw_buf [0] = cpu_to_le32 (buf);
+	qtd->hw_buf [0] = cpu_to_le32 ((u32)addr);
+	qtd->hw_buf_hi [0] = cpu_to_le32 ((u32)(addr >> 32));
 	count = 0x1000 - (buf & 0x0fff);	/* rest of that page */
 	if (likely (len < count))		/* ... iff needed */
 		count = len;
@@ -59,7 +61,7 @@ qtd_fill (struct ehci_qtd *qtd, dma_addr_t buf, size_t len, int token)
 
 		/* per-qtd limit: from 16K to 20K (best alignment) */
 		for (i = 1; count < len && i < 5; i++) {
-			u64	addr = buf;
+			addr = buf;
 			qtd->hw_buf [i] = cpu_to_le32 ((u32)addr);
 			qtd->hw_buf_hi [i] = cpu_to_le32 ((u32)(addr >> 32));
 			buf += 0x1000;
@@ -157,30 +159,6 @@ static inline void qtd_copy_status (struct urb *urb, size_t length, u32 token)
 	}
 }
 
-static void ehci_urb_complete (
-	struct ehci_hcd		*ehci,
-	dma_addr_t		addr,
-	struct urb		*urb
-) {
-	if (urb->transfer_buffer_length && usb_pipein (urb->pipe))
-		pci_dma_sync_single (ehci->hcd.pdev, addr,
-			urb->transfer_buffer_length,
-			PCI_DMA_FROMDEVICE);
-
-	/* cleanse status if we saw no error */
-	if (likely (urb->status == -EINPROGRESS)) {
-		if (urb->actual_length != urb->transfer_buffer_length
-				&& (urb->transfer_flags & URB_SHORT_NOT_OK))
-			urb->status = -EREMOTEIO;
-		else
-			urb->status = 0;
-	}
-
-	/* only report unlinks once */
-	if (likely (urb->status != -ENOENT && urb->status != -ENOTCONN))
-		urb->complete (urb);
-}
-
 /* urb->lock ignored from here on (hcd is done with urb) */
 
 static void ehci_urb_done (
@@ -188,6 +166,11 @@ static void ehci_urb_done (
 	dma_addr_t		addr,
 	struct urb		*urb
 ) {
+#ifdef	INTR_AUTOMAGIC
+	struct urb		*resubmit = 0;
+	struct usb_device	*dev = 0;
+#endif
+
 	if (urb->transfer_buffer_length)
 		pci_unmap_single (ehci->hcd.pdev,
 			addr,
@@ -196,7 +179,23 @@ static void ehci_urb_done (
 			    ? PCI_DMA_FROMDEVICE
 			    : PCI_DMA_TODEVICE);
 	if (likely (urb->hcpriv != 0)) {
-		qh_put (ehci, (struct ehci_qh *) urb->hcpriv);
+		struct ehci_qh	*qh = (struct ehci_qh *) urb->hcpriv;
+
+		/* S-mask in a QH means it's an interrupt urb */
+		if ((qh->hw_info2 & cpu_to_le32 (0x00ff)) != 0) {
+
+			/* ... update hc-wide periodic stats (for usbfs) */
+			ehci->hcd.self.bandwidth_int_reqs--;
+
+#ifdef	INTR_AUTOMAGIC
+			if (!((urb->status == -ENOENT)
+					|| (urb->status == -ECONNRESET))) {
+				resubmit = usb_get_urb (urb);
+				dev = urb->dev;
+			}
+#endif
+		}
+		qh_put (ehci, qh);
 		urb->hcpriv = 0;
 	}
 
@@ -208,33 +207,46 @@ static void ehci_urb_done (
 			urb->status = 0;
 	}
 
-	/* hand off urb ownership */
 	usb_hcd_giveback_urb (&ehci->hcd, urb);
+
+#ifdef	INTR_AUTOMAGIC
+	if (resubmit && ((urb->status == -ENOENT)
+				|| (urb->status == -ECONNRESET))) {
+		usb_put_urb (resubmit);
+		resubmit = 0;
+	}
+	// device drivers will soon be doing something like this
+	if (resubmit) {
+		int	status;
+
+		resubmit->dev = dev;
+		status = usb_submit_urb (resubmit, SLAB_KERNEL);
+		if (status != 0)
+			err ("can't resubmit interrupt urb %p: status %d",
+					resubmit, status);
+		usb_put_urb (resubmit);
+	}
+#endif
 }
 
 
 /*
  * Process completed qtds for a qh, issuing completions if needed.
- * When freeing:  frees qtds, unmaps buf, returns URB to driver.
- * When not freeing (queued periodic qh):  retain qtds, mapping, and urb.
+ * Frees qtds, unmaps buf, returns URB to driver.
  * Races up to qh->hw_current; returns number of urb completions.
  */
-static int
-qh_completions (
-	struct ehci_hcd		*ehci,
-	struct ehci_qh		*qh,
-	int			freeing
-) {
+static void
+qh_completions (struct ehci_hcd *ehci, struct ehci_qh *qh)
+{
 	struct ehci_qtd		*qtd, *last;
 	struct list_head	*next, *qtd_list = &qh->qtd_list;
 	int			unlink = 0, halted = 0;
 	unsigned long		flags;
-	int			retval = 0;
 
 	spin_lock_irqsave (&ehci->lock, flags);
 	if (unlikely (list_empty (qtd_list))) {
 		spin_unlock_irqrestore (&ehci->lock, flags);
-		return retval;
+		return;
 	}
 
 	/* scan QTDs till end of list, or we reach an active one */
@@ -251,14 +263,8 @@ qh_completions (
 			if (likely (last->urb != urb)) {
 				/* complete() can reenter this HCD */
 				spin_unlock_irqrestore (&ehci->lock, flags);
-				if (likely (freeing != 0))
-					ehci_urb_done (ehci, last->buf_dma,
-						last->urb);
-				else
-					ehci_urb_complete (ehci, last->buf_dma,
-						last->urb);
+				ehci_urb_done (ehci, last->buf_dma, last->urb);
 				spin_lock_irqsave (&ehci->lock, flags);
-				retval++;
 			}
 
 			/* qh overlays can have HC's old cached copies of
@@ -270,7 +276,6 @@ qh_completions (
 				qh->hw_qtd_next = last->hw_next;
 			}
 
-			if (likely (freeing != 0))
 			ehci_qtd_free (ehci, last);
 			last = 0;
 		}
@@ -288,7 +293,7 @@ qh_completions (
 
 		/* fault: unlink the rest, since this qtd saw an error? */
 		if (unlikely ((token & QTD_STS_HALT) != 0)) {
-			freeing = unlink = 1;
+			unlink = 1;
 			/* status copied below */
 
 		/* QH halts only because of fault (above) or unlink (here). */
@@ -296,13 +301,14 @@ qh_completions (
 
 			/* unlinking everything because of HC shutdown? */
 			if (ehci->hcd.state == USB_STATE_HALT) {
-				freeing = unlink = 1;
+				unlink = 1;
 
 			/* explicit unlink, maybe starting here? */
 			} else if (qh->qh_state == QH_STATE_IDLE
 					&& (urb->status == -ECONNRESET
+						|| urb->status == -ESHUTDOWN
 						|| urb->status == -ENOENT)) {
-				freeing = unlink = 1;
+				unlink = 1;
 
 			/* QH halted to unlink urbs _after_ this?  */
 			} else if (!unlink && (token & QTD_STS_ACTIVE) != 0) {
@@ -312,7 +318,7 @@ qh_completions (
 
 			/* unlink the rest?  once we start unlinking, after
 			 * a fault or explicit unlink, we unlink all later
-			 * urbs.  usb spec requires that.
+			 * urbs.  usb spec requires that for faults...
 			 */
 			if (unlink && urb->status == -EINPROGRESS)
 				urb->status = -ECONNRESET;
@@ -330,31 +336,7 @@ qh_completions (
 		qtd_copy_status (urb, qtd->length, token);
 		spin_unlock (&urb->lock);
 
-		/*
-		 * NOTE:  this won't work right with interrupt urbs that
-		 * need multiple qtds ... only the first scan of qh->qtd_list
-		 * starts at the right qtd, yet multiple scans could happen
-		 * for transfers that are scheduled across multiple uframes. 
-		 * (Such schedules are not currently allowed!)
-		 */
-		if (likely (freeing != 0))
 		list_del (&qtd->qtd_list);
-		else {
-			/* restore everything the HC could change
-			 * from an interrupt QTD
-			 */
-			qtd->hw_token = (qtd->hw_token
-					& __constant_cpu_to_le32 (0x8300))
-				| cpu_to_le32 (qtd->length << 16)
-				| __constant_cpu_to_le32 (QTD_STS_ACTIVE
-					| (EHCI_TUNE_CERR << 10));
-			qtd->hw_buf [0] &= ~__constant_cpu_to_le32 (0x0fff);
-
-			/* this offset, and the length above,
-			 * are likely wrong on QTDs #2..N
-			 */
-			qtd->hw_buf [0] |= cpu_to_le32 (0x0fff & qtd->buf_dma);
-		}
 
 #if 0
 		if (urb->status == -EINPROGRESS)
@@ -382,14 +364,9 @@ qh_completions (
 
 	/* last urb's completion might still need calling */
 	if (likely (last != 0)) {
-		if (likely (freeing != 0)) {
 		ehci_urb_done (ehci, last->buf_dma, last->urb);
 		ehci_qtd_free (ehci, last);
-		} else
-			ehci_urb_complete (ehci, last->buf_dma, last->urb);
-		retval++;
 	}
-	return retval;
 }
 
 /*-------------------------------------------------------------------------*/
@@ -450,6 +427,7 @@ qh_urb_transaction (
 	struct ehci_qtd		*qtd, *qtd_prev;
 	dma_addr_t		buf, map_buf;
 	int			len, maxpacket;
+	int			is_input;
 	u32			token;
 
 	/*
@@ -495,10 +473,11 @@ qh_urb_transaction (
 	 * data transfer stage:  buffer setup
 	 */
 	len = urb->transfer_buffer_length;
+	is_input = usb_pipein (urb->pipe);
 	if (likely (len > 0)) {
 		buf = map_buf = pci_map_single (ehci->hcd.pdev,
 			urb->transfer_buffer, len,
-			usb_pipein (urb->pipe)
+			is_input
 			    ? PCI_DMA_FROMDEVICE
 			    : PCI_DMA_TODEVICE);
 		if (unlikely (!buf))
@@ -506,12 +485,11 @@ qh_urb_transaction (
 	} else
 		buf = map_buf = 0;
 
-	if (!buf || usb_pipein (urb->pipe))
+	if (!buf || is_input)
 		token |= (1 /* "in" */ << 8);
 	/* else it's already initted to "out" pid (0 << 8) */
 
-	maxpacket = usb_maxpacket (urb->dev, urb->pipe,
-			usb_pipeout (urb->pipe));
+	maxpacket = usb_maxpacket (urb->dev, urb->pipe, !is_input) & 0x03ff;
 
 	/*
 	 * buffer gets wrapped in one or more qtds;
@@ -607,6 +585,11 @@ clear_toggle (struct usb_device *udev, int ep, int is_out, struct ehci_qh *qh)
 // That'd mean updating how usbcore talks to HCDs. (2.5?)
 
 
+// high bandwidth multiplier, as encoded in highspeed endpoint descriptors
+#define hb_mult(wMaxPacketSize) (1 + (((wMaxPacketSize) >> 11) & 0x03))
+// ... and packet size, for any kind of endpoint descriptor
+#define max_packet(wMaxPacketSize) ((wMaxPacketSize) & 0x03ff)
+
 /*
  * Each QH holds a qtd list; a QH is used for everything except iso.
  *
@@ -624,6 +607,8 @@ ehci_qh_make (
 ) {
 	struct ehci_qh		*qh = ehci_qh_alloc (ehci, flags);
 	u32			info1 = 0, info2 = 0;
+	int			is_input, type;
+	int			maxp = 0;
 
 	if (!qh)
 		return qh;
@@ -634,6 +619,53 @@ ehci_qh_make (
 	info1 |= usb_pipeendpoint (urb->pipe) << 8;
 	info1 |= usb_pipedevice (urb->pipe) << 0;
 
+	is_input = usb_pipein (urb->pipe);
+	type = usb_pipetype (urb->pipe);
+	maxp = usb_maxpacket (urb->dev, urb->pipe, !is_input);
+
+	/* Compute interrupt scheduling parameters just once, and save.
+	 * - allowing for high bandwidth, how many nsec/uframe are used?
+	 * - split transactions need a second CSPLIT uframe; same question
+	 * - splits also need a schedule gap (for full/low speed I/O)
+	 * - qh has a polling interval
+	 *
+	 * For control/bulk requests, the HC or TT handles these.
+	 */
+	if (type == PIPE_INTERRUPT) {
+		qh->usecs = usb_calc_bus_time (USB_SPEED_HIGH, is_input, 0,
+				hb_mult (maxp) * max_packet (maxp));
+		qh->start = NO_FRAME;
+
+		if (urb->dev->speed == USB_SPEED_HIGH) {
+			qh->c_usecs = 0;
+			qh->gap_uf = 0;
+
+			/* FIXME handle HS periods of less than 1 frame. */
+			qh->period = urb->interval >> 3;
+			if (qh->period < 1) {
+				dbg ("intr period %d uframes, NYET!",
+						urb->interval);
+				qh = 0;
+				goto done;
+			}
+		} else {
+			/* gap is f(FS/LS transfer times) */
+			qh->gap_uf = 1 + usb_calc_bus_time (urb->dev->speed,
+					is_input, 0, maxp) / (125 * 1000);
+
+			/* FIXME this just approximates SPLIT/CSPLIT times */
+			if (is_input) {		// SPLIT, gap, CSPLIT+DATA
+				qh->c_usecs = qh->usecs + HS_USECS (0);
+				qh->usecs = HS_USECS (1);
+			} else {		// SPLIT+DATA, gap, CSPLIT
+				qh->usecs += HS_USECS (1);
+				qh->c_usecs = HS_USECS (0);
+			}
+
+			qh->period = urb->interval;
+		}
+	}
+
 	/* using TT? */
 	switch (urb->dev->speed) {
 	case USB_SPEED_LOW:
@@ -643,67 +675,63 @@ ehci_qh_make (
 	case USB_SPEED_FULL:
 		/* EPS 0 means "full" */
 		info1 |= (EHCI_TUNE_RL_TT << 28);
-		if (usb_pipecontrol (urb->pipe)) {
+		if (type == PIPE_CONTROL) {
 			info1 |= (1 << 27);	/* for TT */
 			info1 |= 1 << 14;	/* toggle from qtd */
 		}
-		info1 |= usb_maxpacket (urb->dev, urb->pipe,
-					usb_pipeout (urb->pipe)) << 16;
+		info1 |= maxp << 16;
 
 		info2 |= (EHCI_TUNE_MULT_TT << 30);
 		info2 |= urb->dev->ttport << 23;
 		info2 |= urb->dev->tt->hub->devnum << 16;
 
-		/* NOTE:  if (usb_pipeint (urb->pipe)) { scheduler sets c-mask }
-		 * ... and a 0.96 scheduler might use FSTN nodes too
-		 */
+		/* NOTE:  if (PIPE_INTERRUPT) { scheduler sets c-mask } */
+
 		break;
 
 	case USB_SPEED_HIGH:		/* no TT involved */
 		info1 |= (2 << 12);	/* EPS "high" */
 		info1 |= (EHCI_TUNE_RL_HS << 28);
-		if (usb_pipecontrol (urb->pipe)) {
+		if (type == PIPE_CONTROL) {
 			info1 |= 64 << 16;	/* usb2 fixed maxpacket */
 			info1 |= 1 << 14;	/* toggle from qtd */
 			info2 |= (EHCI_TUNE_MULT_HS << 30);
-		} else if (usb_pipebulk (urb->pipe)) {
+		} else if (type == PIPE_BULK) {
 			info1 |= 512 << 16;	/* usb2 fixed maxpacket */
 			info2 |= (EHCI_TUNE_MULT_HS << 30);
-		} else {
-			u32	temp;
-			temp = usb_maxpacket (urb->dev, urb->pipe,
-						usb_pipeout (urb->pipe));
-			info1 |= (temp & 0x3ff) << 16;	/* maxpacket */
-			/* HS intr can be "high bandwidth" */
-			temp = 1 + ((temp >> 11) & 0x03);
-			info2 |= temp << 30;		/* mult */
+		} else {		/* PIPE_INTERRUPT */
+			info1 |= max_packet (maxp) << 16;
+			info2 |= hb_mult (maxp) << 30;
 		}
 		break;
-	default:
 #ifdef DEBUG
+	default:
 		BUG ();
 #endif
 	}
 
-	/* NOTE:  if (usb_pipeint (urb->pipe)) { scheduler sets s-mask } */
+	/* NOTE:  if (PIPE_INTERRUPT) { scheduler sets s-mask } */
 
 	qh->qh_state = QH_STATE_IDLE;
 	qh->hw_info1 = cpu_to_le32 (info1);
 	qh->hw_info2 = cpu_to_le32 (info2);
 
 	/* initialize sw and hw queues with these qtds */
+	if (!list_empty (qtd_list)) {
 		list_splice (qtd_list, &qh->qtd_list);
 		qh_update (qh, list_entry (qtd_list->next, struct ehci_qtd, qtd_list));
+	} else {
+		qh->hw_qtd_next = qh->hw_alt_next = EHCI_LIST_END;
+	}
 
 	/* initialize data toggle state */
-	if (!usb_pipecontrol (urb->pipe))
-		clear_toggle (urb->dev,
-			usb_pipeendpoint (urb->pipe),
-			usb_pipeout (urb->pipe),
-			qh);
+	clear_toggle (urb->dev, usb_pipeendpoint (urb->pipe), !is_input, qh);
 
+done:
 	return qh;
 }
+#undef hb_mult
+#undef hb_packet
 
 /*-------------------------------------------------------------------------*/
 
@@ -745,50 +773,48 @@ static void qh_link_async (struct ehci_hcd *ehci, struct ehci_qh *qh)
 
 /*-------------------------------------------------------------------------*/
 
-static int
-submit_async (
+/*
+ * For control/bulk/interrupt, return QH with these TDs appended.
+ * Allocates and initializes the QH if necessary.
+ * Returns null if it can't allocate a QH it needs to.
+ * If the QH has TDs (urbs) already, that's great.
+ */
+static struct ehci_qh *qh_append_tds (
 	struct ehci_hcd		*ehci,
 	struct urb		*urb,
 	struct list_head	*qtd_list,
-	int			mem_flags
-) {
-	struct ehci_qtd		*qtd;
-	struct hcd_dev		*dev;
-	int			epnum;
-	unsigned long		flags;
+	int			epnum,
+	void			**ptr
+)
+{
 	struct ehci_qh		*qh = 0;
 
-	qtd = list_entry (qtd_list->next, struct ehci_qtd, qtd_list);
-	dev = (struct hcd_dev *)urb->dev->hcpriv;
-	epnum = usb_pipeendpoint (urb->pipe);
-	if (usb_pipein (urb->pipe))
-		epnum |= 0x10;
-
-	vdbg ("%s: submit_async urb %p len %d ep %d-%s qtd %p [qh %p]",
-		ehci->hcd.self.bus_name, urb, urb->transfer_buffer_length,
-		epnum & 0x0f, (epnum & 0x10) ? "in" : "out",
-		qtd, dev ? dev->ep [epnum] : (void *)~0);
-
-	spin_lock_irqsave (&ehci->lock, flags);
-
-	qh = (struct ehci_qh *) dev->ep [epnum];
+	qh = (struct ehci_qh *) *ptr;
 	if (likely (qh != 0)) {
-		u32	hw_next = QTD_NEXT (qtd->qtd_dma);
+		struct ehci_qtd	*qtd;
+
+		if (unlikely (list_empty (qtd_list)))
+			qtd = 0;
+		else
+			qtd = list_entry (qtd_list->next, struct ehci_qtd,
+					qtd_list);
 
 		/* maybe patch the qh used for set_address */
 		if (unlikely (epnum == 0
 				&& le32_to_cpu (qh->hw_info1 & 0x7f) == 0))
 			qh->hw_info1 |= cpu_to_le32 (usb_pipedevice(urb->pipe));
 
-		/* is an URB is queued to this qh already? */
-		if (unlikely (!list_empty (&qh->qtd_list))) {
+		/* append to tds already queued to this qh? */
+		if (unlikely (!list_empty (&qh->qtd_list) && qtd)) {
 			struct ehci_qtd		*last_qtd;
 			int			short_rx = 0;
+			u32			hw_next;
 
 			/* update the last qtd's "next" pointer */
 			// dbg_qh ("non-empty qh", ehci, qh);
 			last_qtd = list_entry (qh->qtd_list.prev,
 					struct ehci_qtd, qtd_list);
+			hw_next = QTD_NEXT (qtd->qtd_dma);
 			last_qtd->hw_next = hw_next;
 
 			/* previous urb allows short rx? maybe optimize. */
@@ -803,6 +829,7 @@ submit_async (
 			 * Interrupt code must cope with case of HC having it
 			 * cached, and clobbering these updates.
 			 * ... complicates getting rid of extra interrupts!
+			 * (Or:  use dummy td, so cache always stays valid.)
 			 */
 			if (qh->hw_current == cpu_to_le32 (last_qtd->qtd_dma)) {
 				wmb ();
@@ -822,13 +849,13 @@ submit_async (
 			 */
 
 			/* usb_clear_halt() means qh data toggle gets reset */
-			if (usb_pipebulk (urb->pipe)
-					&& unlikely (!usb_gettoggle (urb->dev,
+			if (unlikely (!usb_gettoggle (urb->dev,
 						(epnum & 0x0f),
 						!(epnum & 0x10)))) {
 				clear_toggle (urb->dev,
 					epnum & 0x0f, !(epnum & 0x10), qh);
 			}
+			if (qtd)
 				qh_update (qh, qtd);
 		}
 		list_splice (qtd_list, qh->qtd_list.prev);
@@ -836,17 +863,47 @@ submit_async (
 	} else {
 		/* can't sleep here, we have ehci->lock... */
 		qh = ehci_qh_make (ehci, urb, qtd_list, SLAB_ATOMIC);
-		if (likely (qh != 0)) {
-			// dbg_qh ("new qh", ehci, qh);
-			dev->ep [epnum] = qh;
-		}
+		// if (qh) dbg_qh ("new qh", ehci, qh);
+		*ptr = qh;
 	}
+	if (qh)
+		urb->hcpriv = qh_get (qh);
+	return qh;
+}
+
+/*-------------------------------------------------------------------------*/
+
+static int
+submit_async (
+	struct ehci_hcd		*ehci,
+	struct urb		*urb,
+	struct list_head	*qtd_list,
+	int			mem_flags
+) {
+	struct ehci_qtd		*qtd;
+	struct hcd_dev		*dev;
+	int			epnum;
+	unsigned long		flags;
+	struct ehci_qh		*qh = 0;
+
+	qtd = list_entry (qtd_list->next, struct ehci_qtd, qtd_list);
+	dev = (struct hcd_dev *)urb->dev->hcpriv;
+	epnum = usb_pipeendpoint (urb->pipe);
+	if (usb_pipein (urb->pipe))
+		epnum |= 0x10;
+
+	vdbg ("%s: submit_async urb %p len %d ep %d-%s qtd %p [qh %p]",
+		ehci->hcd.self.bus_name, urb, urb->transfer_buffer_length,
+		epnum & 0x0f, (epnum & 0x10) ? "in" : "out",
+		qtd, dev ? dev->ep [epnum] : (void *)~0);
+
+	spin_lock_irqsave (&ehci->lock, flags);
+	qh = qh_append_tds (ehci, urb, qtd_list, epnum, &dev->ep [epnum]);
 
 	/* Control/bulk operations through TTs don't need scheduling,
 	 * the HC and TT handle it when the TT has a buffer ready.
 	 */
 	if (likely (qh != 0)) {
-		urb->hcpriv = qh_get (qh);
 		if (likely (qh->qh_state == QH_STATE_IDLE))
 			qh_link_async (ehci, qh_get (qh));
 	}
@@ -873,7 +930,7 @@ static void end_unlink_async (struct ehci_hcd *ehci)
 	ehci->reclaim = 0;
 	ehci->reclaim_ready = 0;
 
-	qh_completions (ehci, qh, 1);
+	qh_completions (ehci, qh);
 
 	// unlink any urb should now unlink all following urbs, so that
 	// relinking only happens for urbs before the unlinked ones.
@@ -973,13 +1030,15 @@ static void scan_async (struct ehci_hcd *ehci)
 				spin_unlock_irqrestore (&ehci->lock, flags);
 
 				/* concurrent unlink could happen here */
-				qh_completions (ehci, qh, 1);
+				qh_completions (ehci, qh);
 
 				spin_lock_irqsave (&ehci->lock, flags);
 				qh_put (ehci, qh);
 			}
 
-			/* unlink idle entries (reduces PCI usage) */
+			/* unlink idle entries, reducing HC PCI usage as
+			 * well as HCD schedule-scanning costs
+			 */
 			if (list_empty (&qh->qtd_list) && !ehci->reclaim) {
 				if (qh->qh_next.qh != qh) {
 					// dbg ("irq/empty");
@@ -987,6 +1046,7 @@ static void scan_async (struct ehci_hcd *ehci)
 				} else {
 					// FIXME:  arrange to stop
 					// after it's been idle a while.
+					// stop/restart isn't free...
 				}
 			}
 			qh = qh->qh_next.qh;

drivers/usb/host/ehci-sched.c

@@ -220,31 +220,31 @@ static int disable_periodic (struct ehci_hcd *ehci)
 
 /*-------------------------------------------------------------------------*/
 
+// FIXME microframe periods not yet handled
+
 static void intr_deschedule (
 	struct ehci_hcd	*ehci,
-	unsigned	frame,
 	struct ehci_qh	*qh,
-	unsigned	period
+	int		wait
 ) {
 	unsigned long	flags;
 	int		status;
-
-	period >>= 3;		// FIXME microframe periods not handled yet
+	unsigned	frame = qh->start;
 
 	spin_lock_irqsave (&ehci->lock, flags);
 
 	do {
 		periodic_unlink (ehci, frame, qh);
 		qh_put (ehci, qh);
-		frame += period;
+		frame += qh->period;
 	} while (frame < ehci->periodic_size);
 
 	qh->qh_state = QH_STATE_UNLINK;
 	qh->qh_next.ptr = 0;
-	ehci->periodic_urbs--;
+	ehci->periodic_sched--;
 
 	/* maybe turn off periodic schedule */
-	if (!ehci->periodic_urbs)
+	if (!ehci->periodic_sched)
 		status = disable_periodic (ehci);
 	else {
 		status = 0;
@@ -258,21 +258,35 @@ static void intr_deschedule (
 	 * (yeech!) to be sure it's done.
 	 * No other threads may be mucking with this qh.
 	 */
-	if (!status && ((ehci_get_frame (&ehci->hcd) - frame) % period) == 0)
+	if (((ehci_get_frame (&ehci->hcd) - frame) % qh->period) == 0) {
+		if (wait) {
 			udelay (125);
+			qh->hw_next = EHCI_LIST_END;
+		} else {
+			/* we may not be IDLE yet, but if the qh is empty
+			 * the race is very short.  then if qh also isn't
+			 * rescheduled soon, it won't matter.  otherwise...
+			 */
+			vdbg ("intr_deschedule...");
+		}
+	} else
+		qh->hw_next = EHCI_LIST_END;
 
 	qh->qh_state = QH_STATE_IDLE;
-	qh->hw_next = EHCI_LIST_END;
+
+	/* update per-qh bandwidth utilization (for usbfs) */
+	ehci->hcd.self.bandwidth_allocated -= 
+		(qh->usecs + qh->c_usecs) / qh->period;
 
 	vdbg ("descheduled qh %p, per = %d frame = %d count = %d, urbs = %d",
-		qh, period, frame,
-		atomic_read (&qh->refcount), ehci->periodic_urbs);
+		qh, qh->period, frame,
+		atomic_read (&qh->refcount), ehci->periodic_sched);
 }
 
 static int check_period (
 	struct ehci_hcd *ehci, 
 	unsigned	frame,
-	int		uframe,
+	unsigned	uframe,
 	unsigned	period,
 	unsigned	usecs
 ) {
@@ -309,195 +323,108 @@ static int check_period (
 	return 1;
 }
 
-static int intr_submit (
+static int check_intr_schedule (
 	struct ehci_hcd		*ehci, 
-	struct urb		*urb,
-	struct list_head	*qtd_list,
-	int			mem_flags
-) {
-	unsigned		epnum, period;
-	unsigned short		usecs, c_usecs, gap_uf;
-	unsigned long		flags;
-	struct ehci_qh		*qh;
-	struct hcd_dev		*dev;
-	int			is_input;
-	int			status = 0;
-
-	/* get endpoint and transfer/schedule data */
-	epnum = usb_pipeendpoint (urb->pipe);
-	is_input = usb_pipein (urb->pipe);
-	if (is_input)
-		epnum |= 0x10;
+	unsigned		frame,
+	unsigned		uframe,
+	const struct ehci_qh	*qh,
+	u32			*c_maskp
+)
+{
+    	int		retval = -ENOSPC;
 
-	/*
-	 * HS interrupt transfers are simple -- only one microframe.  FS/LS
-	 * interrupt transfers involve a SPLIT in one microframe and CSPLIT
-	 * sometime later.  We need to know how much time each will be
-	 * needed in each microframe and, for FS/LS, how many microframes
-	 * separate the two in the best case.
-	 */
-	usecs = usb_calc_bus_time (USB_SPEED_HIGH, is_input, 0,
-			urb->transfer_buffer_length);
-	if (urb->dev->speed == USB_SPEED_HIGH) {
-		gap_uf = 0;
-		c_usecs = 0;
-
-		/* FIXME handle HS periods of less than 1 frame. */
-		period = urb->interval >> 3;
-		if (period < 1) {
-			dbg ("intr period %d uframes, NYET!", urb->interval);
-			status = -EINVAL;
+	if (!check_period (ehci, frame, uframe, qh->period, qh->usecs))
+		goto done;
+	if (!qh->c_usecs) {
+		retval = 0;
+		*c_maskp = cpu_to_le32 (0);
 		goto done;
-		}
-	} else {
-		/* gap is a function of full/low speed transfer times */
-		gap_uf = 1 + usb_calc_bus_time (urb->dev->speed, is_input, 0,
-				urb->transfer_buffer_length) / (125 * 1000);
-
-		/* FIXME this just approximates SPLIT/CSPLIT times */
-		if (is_input) {		// SPLIT, gap, CSPLIT+DATA
-			c_usecs = usecs + HS_USECS (0);
-			usecs = HS_USECS (1);
-		} else {		// SPLIT+DATA, gap, CSPLIT
-			usecs = usecs + HS_USECS (1);
-			c_usecs = HS_USECS (0);
-		}
-
-		period = urb->interval;
 	}
 
-	/*
-	 * NOTE: current completion/restart logic doesn't handle more than
-	 * one qtd in a periodic qh ... 16-20 KB/urb is pretty big for this.
-	 * such big requests need many periods to transfer.
+	/* This is a split transaction; check the bandwidth available for
+	 * the completion too.  Check both worst and best case gaps: worst
+	 * case is SPLIT near uframe end, and CSPLIT near start ... best is
+	 * vice versa.  Difference can be almost two uframe times, but we
+	 * reserve unnecessary bandwidth (waste it) this way.  (Actually
+	 * even better cases exist, like immediate device NAK.)
+	 *
+	 * FIXME don't even bother unless we know this TT is idle in that
+	 * range of uframes ... for now, check_period() allows only one
+	 * interrupt transfer per frame, so needn't check "TT busy" status
+	 * when scheduling a split (QH, SITD, or FSTN).
 	 *
-	 * FIXME want to change hcd core submit model to expect queuing
-	 * for all transfer types ... not just ISO and (with flag) BULK.
-	 * that means: getting rid of this check; handling the "interrupt
-	 * urb already queued" case below like bulk queuing is handled (no
-	 * errors possible!); and completly getting rid of that annoying
-	 * qh restart logic.  simpler/smaller overall, and more flexible.
+	 * FIXME ehci 0.96 and above can use FSTNs
 	 */
-	if (unlikely (qtd_list->next != qtd_list->prev)) {
-		dbg ("only one intr qtd per urb allowed"); 
-		status = -EINVAL;
+	if (!check_period (ehci, frame, uframe + qh->gap_uf + 1,
+				qh->period, qh->c_usecs))
+		goto done;
+	if (!check_period (ehci, frame, uframe + qh->gap_uf,
+				qh->period, qh->c_usecs))
 		goto done;
-	}
-
-	spin_lock_irqsave (&ehci->lock, flags);
 
-	/* get the qh (must be empty and idle) */
-	dev = (struct hcd_dev *)urb->dev->hcpriv;
-	qh = (struct ehci_qh *) dev->ep [epnum];
-	if (qh) {
-		/* only allow one queued interrupt urb per EP */
-		if (unlikely (qh->qh_state != QH_STATE_IDLE
-				|| !list_empty (&qh->qtd_list))) {
-			dbg ("interrupt urb already queued");
-			status = -EBUSY;
-		} else {
-			/* maybe reset hardware's data toggle in the qh */
-			if (unlikely (!usb_gettoggle (urb->dev, epnum & 0x0f,
-					!(epnum & 0x10)))) {
-				qh->hw_token |=
-					__constant_cpu_to_le32 (QTD_TOGGLE);
-				usb_settoggle (urb->dev, epnum & 0x0f,
-					!(epnum & 0x10), 1);
-			}
-			/* trust the QH was set up as interrupt ... */
-			list_splice (qtd_list, &qh->qtd_list);
-			qh_update (qh, list_entry (qtd_list->next,
-						struct ehci_qtd, qtd_list));
-			qtd_list = &qh->qtd_list;
-		}
-	} else {
-		/* can't sleep here, we have ehci->lock... */
-		qh = ehci_qh_make (ehci, urb, qtd_list, SLAB_ATOMIC);
-		if (likely (qh != 0)) {
-			// dbg ("new INTR qh %p", qh);
-			dev->ep [epnum] = qh;
-			qtd_list = &qh->qtd_list;
-		} else
-			status = -ENOMEM;
-	}
+	*c_maskp = cpu_to_le32 (0x03 << (8 + uframe + qh->gap_uf));
+	retval = 0;
+done:
+	return retval;
+}
 
-	/* Schedule this periodic QH. */
-	if (likely (status == 0)) {
-		unsigned	frame = period;
+static int qh_schedule (struct ehci_hcd *ehci, struct ehci_qh *qh)
+{
+	int 		status;
+	unsigned	uframe;
+	u32		c_mask;
+	unsigned	frame;		/* 0..(qh->period - 1), or NO_FRAME */
 
 	qh->hw_next = EHCI_LIST_END;
-		qh->usecs = usecs;
-		qh->c_usecs = c_usecs;
+	frame = qh->start;
 
-		urb->hcpriv = qh_get (qh);
+	/* reuse the previous schedule slots, if we can */
+	if (frame < qh->period) {
+		uframe = ffs (le32_to_cpup (&qh->hw_info2) & 0x00ff);
+		status = check_intr_schedule (ehci, frame, --uframe,
+				qh, &c_mask);
+	} else {
+		uframe = 0;
+		c_mask = 0;
 		status = -ENOSPC;
+	}
 
-		/* pick a set of schedule slots, link the QH into them */
-		do {
-			int	uframe;
-			u32	c_mask = 0;
-
-			/* pick a set of slots such that all uframes have
-			 * enough periodic bandwidth available.
+	/* else scan the schedule to find a group of slots such that all
+	 * uframes have enough periodic bandwidth available.
 	 */
-			frame--;
+	if (status) {
+		frame = qh->period - 1;
+		do {
 			for (uframe = 0; uframe < 8; uframe++) {
-				if (check_period (ehci, frame, uframe,
-						period, usecs) == 0)
-					continue;
-
-				/* If this is a split transaction, check the
-				 * bandwidth available for the completion
-				 * too.  check both best and worst case gaps:
-				 * worst case is SPLIT near uframe end, and
-				 * CSPLIT near start ... best is vice versa.
-				 * Difference can be almost two uframe times.
-				 *
-				 * FIXME don't even bother unless we know
-				 * this TT is idle in that uframe ... right
-				 * now we know only one interrupt transfer
-				 * will be scheduled per frame, so we don't
-				 * need to update/check TT state when we
-				 * schedule a split (QH, SITD, or FSTN).
-				 *
-				 * FIXME ehci 0.96 and above can use FSTNs
-				 */
-				if (!c_usecs)
-				    	break;
-				if (check_period (ehci, frame,
-						uframe + gap_uf,
-						period, c_usecs) == 0)
-					continue;
-				if (check_period (ehci, frame,
-						uframe + gap_uf + 1,
-						period, c_usecs) == 0)
-					continue;
-
-				c_mask = 0x03 << (8 + uframe + gap_uf);
-				c_mask = cpu_to_le32 (c_mask);
+				status = check_intr_schedule (ehci,
+						frame, uframe, qh,
+						&c_mask);
+				if (status == 0)
 					break;
 			}
-			if (uframe == 8)
-				continue;
-
-			/* QH will run once each period, starting there  */
-			urb->start_frame = frame;
-			status = 0;
+		} while (status && --frame);
+		if (status)
+			goto done;
+		qh->start = frame;
 
 		/* reset S-frame and (maybe) C-frame masks */
 		qh->hw_info2 &= ~0xffff;
 		qh->hw_info2 |= cpu_to_le32 (1 << uframe) | c_mask;
-			// dbg_qh ("Schedule INTR qh", ehci, qh);
+	} else
+		dbg ("reused previous qh %p schedule", qh);
 
 	/* stuff into the periodic schedule */
 	qh->qh_state = QH_STATE_LINKED;
-			vdbg ("qh %p usecs %d period %d.0 starting %d.%d",
-				qh, qh->usecs, period, frame, uframe);
+	dbg ("qh %p usecs %d/%d period %d.0 starting %d.%d (gap %d)",
+		qh, qh->usecs, qh->c_usecs,
+		qh->period, frame, uframe, qh->gap_uf);
 	do {
 		if (unlikely (ehci->pshadow [frame].ptr != 0)) {
+
 // FIXME -- just link toward the end, before any qh with a shorter period,
-// AND handle it already being (implicitly) linked into this frame
-// AS WELL AS updating the check_period() logic
+// AND accomodate it already having been linked here (after some other qh)
+// AS WELL AS updating the schedule checking logic
+
 			BUG ();
 		} else {
 			ehci->pshadow [frame].qh = qh_get (qh);
@@ -505,22 +432,64 @@ static int intr_submit (
 				QH_NEXT (qh->qh_dma);
 		}
 		wmb ();
-				frame += period;
+		frame += qh->period;
 	} while (frame < ehci->periodic_size);
 
-			/* update bandwidth utilization records (for usbfs) */
-			usb_claim_bandwidth (urb->dev, urb,
-				(usecs + c_usecs) / period, 0);
+	/* update per-qh bandwidth for usbfs */
+	ehci->hcd.self.bandwidth_allocated += 
+		(qh->usecs + qh->c_usecs) / qh->period;
 
 	/* maybe enable periodic schedule processing */
-			if (!ehci->periodic_urbs++)
+	if (!ehci->periodic_sched++)
 		status = enable_periodic (ehci);
-			break;
+done:
+	return status;
+}
 
-		} while (frame);
+static int intr_submit (
+	struct ehci_hcd		*ehci,
+	struct urb		*urb,
+	struct list_head	*qtd_list,
+	int			mem_flags
+) {
+	unsigned		epnum;
+	unsigned long		flags;
+	struct ehci_qh		*qh;
+	struct hcd_dev		*dev;
+	int			is_input;
+	int			status = 0;
+	struct list_head	empty;
+
+	/* get endpoint and transfer/schedule data */
+	epnum = usb_pipeendpoint (urb->pipe);
+	is_input = usb_pipein (urb->pipe);
+	if (is_input)
+		epnum |= 0x10;
+
+	spin_lock_irqsave (&ehci->lock, flags);
+	dev = (struct hcd_dev *)urb->dev->hcpriv;
+
+	/* get qh and force any scheduling errors */
+	INIT_LIST_HEAD (&empty);
+	qh = qh_append_tds (ehci, urb, &empty, epnum, &dev->ep [epnum]);
+	if (qh == 0) {
+		status = -ENOMEM;
+		goto done;
 	}
-	spin_unlock_irqrestore (&ehci->lock, flags);
+	if (qh->qh_state == QH_STATE_IDLE) {
+		if ((status = qh_schedule (ehci, qh)) != 0)
+			goto done;
+	}
+
+	/* then queue the urb's tds to the qh */
+	qh = qh_append_tds (ehci, urb, qtd_list, epnum, &dev->ep [epnum]);
+	BUG_ON (qh == 0);
+
+	/* ... update usbfs periodic stats */
+	ehci->hcd.self.bandwidth_int_reqs++;
+
 done:
+	spin_unlock_irqrestore (&ehci->lock, flags);
 	if (status)
 		qtd_list_free (ehci, urb, qtd_list);
 
@@ -534,10 +503,6 @@ intr_complete (
 	struct ehci_qh	*qh,
 	unsigned long	flags		/* caller owns ehci->lock ... */
 ) {
-	struct ehci_qtd	*qtd;
-	struct urb	*urb;
-	int		unlinking;
-
 	/* nothing to report? */
 	if (likely ((qh->hw_token & __constant_cpu_to_le32 (QTD_STS_ACTIVE))
 			!= 0))
@@ -547,43 +512,14 @@ intr_complete (
 		return flags;
 	}
 	
-	qtd = list_entry (qh->qtd_list.next, struct ehci_qtd, qtd_list);
-	urb = qtd->urb;
-	unlinking = (urb->status == -ENOENT) || (urb->status == -ECONNRESET);
-
-	/* call any completions, after patching for reactivation */
+	/* handle any completions */
 	spin_unlock_irqrestore (&ehci->lock, flags);
-	/* NOTE:  currently restricted to one qtd per qh! */
-	if (qh_completions (ehci, qh, 0) == 0)
-		urb = 0;
+	qh_completions (ehci, qh);
 	spin_lock_irqsave (&ehci->lock, flags);
 
-	/* never reactivate requests that were unlinked ... */
-	if (likely (urb != 0)) {
-		if (unlinking
-				|| urb->status == -ECONNRESET
-				|| urb->status == -ENOENT
-				// || (urb->dev == null)
-				|| ehci->hcd.state == USB_STATE_HALT)
-			urb = 0;
-		// FIXME look at all those unlink cases ... we always
-		// need exactly one completion that reports unlink.
-		// the one above might not have been it!
-	}
+	if (unlikely (list_empty (&qh->qtd_list)))
+		intr_deschedule (ehci, qh, 0);
 
-	/* normally reactivate */
-	if (likely (urb != 0)) {
-		if (usb_pipeout (urb->pipe))
-			pci_dma_sync_single (ehci->hcd.pdev,
-				qtd->buf_dma,
-				urb->transfer_buffer_length,
-				PCI_DMA_TODEVICE);
-		urb->status = -EINPROGRESS;
-		urb->actual_length = 0;
-
-		/* patch qh and restart */
-		qh_update (qh, qtd);
-	}
 	return flags;
 }
 
@@ -806,7 +742,7 @@ static int get_iso_range (
 
 	/* calculate the legal range [start,max) */
 	now = readl (&ehci->regs->frame_index) + 1;	/* next uframe */
-	if (!ehci->periodic_urbs)
+	if (!ehci->periodic_sched)
 		now += 8;				/* startup delay */
 	now %= mod;
 	end = now + mod;
@@ -926,7 +862,7 @@ itd_schedule (struct ehci_hcd *ehci, struct urb *urb)
 		usb_claim_bandwidth (urb->dev, urb, usecs, 1);
 
 		/* maybe enable periodic schedule processing */
-		if (!ehci->periodic_urbs++) {
+		if (!ehci->periodic_sched++) {
 			if ((status =  enable_periodic (ehci)) != 0) {
 				// FIXME deschedule right away
 				err ("itd_schedule, enable = %d", status);
@@ -1009,8 +945,8 @@ itd_complete (
 	spin_lock_irqsave (&ehci->lock, flags);
 
 	/* defer stopping schedule; completion can submit */
-	ehci->periodic_urbs--;
-	if (!ehci->periodic_urbs)
+	ehci->periodic_sched--;
+	if (!ehci->periodic_sched)
 		(void) disable_periodic (ehci);
 
 	return flags;

drivers/usb/host/ehci.h

@@ -50,7 +50,7 @@ struct ehci_hcd {			/* one per controller */
 
 	union ehci_shadow	*pshadow;	/* mirror hw periodic table */
 	int			next_uframe;	/* scan periodic, start here */
-	unsigned		periodic_urbs;	/* how many urbs scheduled? */
+	unsigned		periodic_sched;	/* periodic activity count */
 
 	/* deferred work from IRQ, etc */
 	struct tasklet_struct	tasklet;
@@ -72,7 +72,7 @@ struct ehci_hcd {			/* one per controller */
 };
 
 /* unwrap an HCD pointer to get an EHCI_HCD pointer */ 
-#define hcd_to_ehci(hcd_ptr) list_entry(hcd_ptr, struct ehci_hcd, hcd)
+#define hcd_to_ehci(hcd_ptr) container_of(hcd_ptr, struct ehci_hcd, hcd)
 
 /* NOTE:  urb->transfer_flags expected to not use this bit !!! */
 #define EHCI_STATE_UNLINK	0x8000		/* urb being unlinked */
@@ -287,12 +287,20 @@ struct ehci_qh {
 	struct list_head	qtd_list;	/* sw qtd list */
 
 	atomic_t		refcount;
-	unsigned short		usecs;		/* intr bandwidth */
-	unsigned short		c_usecs;	/* ... split completion bw */
-	short			qh_state;
+
+	u8			qh_state;
 #define	QH_STATE_LINKED		1		/* HC sees this */
 #define	QH_STATE_UNLINK		2		/* HC may still see this */
 #define	QH_STATE_IDLE		3		/* HC doesn't see this */
+
+	/* periodic schedule info */
+	u8			usecs;		/* intr bandwidth */
+	u8			gap_uf;		/* uframes split/csplit gap */
+	u8			c_usecs;	/* ... split completion bw */
+	unsigned short		period;		/* polling interval */
+	unsigned short		start;		/* where polling starts */
+#define NO_FRAME ((unsigned short)~0)			/* pick new start */
+
 } __attribute__ ((aligned (32)));
 
 /*-------------------------------------------------------------------------*/

drivers/usb/host/ohci-q.c

@@ -938,7 +938,7 @@ static void finish_unlinks (struct ohci_hcd *ohci, u16 tick)
 		/* ED's now officially unlinked, hc doesn't see */
 		ed->state = ED_IDLE;
 		ed->hwINFO &= ~ED_SKIP;
-		ed->hwHeadP &= ~cpu_to_le32 (ED_H);
+		ed->hwHeadP &= ~ED_H;
 		ed->hwNextED = 0;
 
 		/* but if there's work queued, reschedule */

drivers/usb/net/cdc-ether.c

@@ -1170,23 +1170,20 @@ static void * CDCEther_probe( struct usb_device *usb, unsigned int ifnum,
 	if (rc)	{
 		// Nope we couldn't find one we liked.
 		// This device was not meant for us to control.
-		kfree( ether_dev );
-		return	NULL;
+		goto error_all;
 	}
 
 	// Now that we FOUND a configuration. let's try to make the
 	// device go into it.
 	if ( usb_set_configuration( usb, ether_dev->bConfigurationValue ) ) {
 		err("usb_set_configuration() failed");
-		kfree( ether_dev );
-		return NULL;
+		goto error_all;
 	}
 
 	// Now set the communication interface up as required.
 	if (usb_set_interface(usb, ether_dev->comm_bInterfaceNumber, ether_dev->comm_bAlternateSetting)) {
 		err("usb_set_interface() failed");
-		kfree( ether_dev );
-		return NULL;
+		goto error_all;
 	}
 
 	// Only turn traffic on right now if we must...
@@ -1198,8 +1195,7 @@ static void * CDCEther_probe( struct usb_device *usb, unsigned int ifnum,
 		                       ether_dev->data_bInterfaceNumber,
 		                       ether_dev->data_bAlternateSetting_without_traffic)) {
 			err("usb_set_interface() failed");
-			kfree( ether_dev );
-			return NULL;
+			goto error_all;
 		}
 	} else	{
 		// We didn't find an alternate setting for the data
@@ -1209,8 +1205,7 @@ static void * CDCEther_probe( struct usb_device *usb, unsigned int ifnum,
 		                       ether_dev->data_bInterfaceNumber,
 		                       ether_dev->data_bAlternateSetting_with_traffic)) {
 			err("usb_set_interface() failed");
-			kfree( ether_dev );
-			return NULL;
+			goto error_all;
 		}
 	}
 
@@ -1220,8 +1215,7 @@ static void * CDCEther_probe( struct usb_device *usb, unsigned int ifnum,
 		// Hmm...  The kernel is not sharing today...
 		// Fine, we didn't want it anyway...
 		err( "Unable to initialize ethernet device" );
-		kfree( ether_dev );
-		return	NULL;
+		goto error_all;
 	}
 
 	// Now that we have an ethernet device, let's set it up
@@ -1265,6 +1259,14 @@ static void * CDCEther_probe( struct usb_device *usb, unsigned int ifnum,
 
 	// Okay, we are finally done...
 	return NULL;
+
+	// bailing out with our tail between our knees
+error_all:
+	usb_free_urb(ether_dev->tx_urb);
+	usb_free_urb(ether_dev->rx_urb);
+	usb_free_urb(ether_dev->intr_urb);
+	kfree( ether_dev );
+	return	NULL;
 }
 
 

drivers/usb/storage/scsiglue.c

@@ -147,7 +147,8 @@ static int queuecommand( Scsi_Cmnd *srb , void (*done)(Scsi_Cmnd *))
 	srb->host_scribble = (unsigned char *)us;
 
 	/* enqueue the command */
-	BUG_ON(atomic_read(&us->sm_state) != US_STATE_IDLE || us->srb != NULL);
+	BUG_ON(atomic_read(&us->sm_state) != US_STATE_IDLE);
+	BUG_ON(us->srb != NULL);
 	srb->scsi_done = done;
 	us->srb = srb;
 

include/linux/usb.h

@@ -734,6 +734,7 @@ extern void usb_deregister_dev(int num_minors, int start_minor);
  */
 #define URB_SHORT_NOT_OK	0x0001	/* report short reads as errors */
 #define USB_ISO_ASAP		0x0002	/* iso-only, urb->start_frame ignored */
+#define URB_NO_DMA_MAP		0x0004	/* urb->*_dma are valid on submit */
 #define USB_ASYNC_UNLINK	0x0008	/* usb_unlink_urb() returns asap */
 #define USB_NO_FSBR		0x0020	/* UHCI-specific */
 #define USB_ZERO_PACKET		0x0040	/* Finish bulk OUTs with short packet */
@@ -771,11 +772,15 @@ typedef void (*usb_complete_t)(struct urb *);
  * @transfer_flags: A variety of flags may be used to affect how URB
  *	submission, unlinking, or operation are handled.  Different
  *	kinds of URB can use different flags.
- * @transfer_buffer: For non-iso transfers, this identifies the buffer
- *	to (or from) which the I/O request will be performed.  This
- *	buffer must be suitable for DMA; allocate it with kmalloc()
+ * @transfer_buffer:  This identifies the buffer to (or from) which
+ * 	the I/O request will be performed (unless URB_NO_DMA_MAP is set).
+ *	This buffer must be suitable for DMA; allocate it with kmalloc()
  *	or equivalent.  For transfers to "in" endpoints, contents of
- *	this buffer will be modified.
+ *	this buffer will be modified.  This buffer is used for data
+ *	phases of control transfers.
+ * @transfer_dma: When transfer_flags includes URB_NO_DMA_MAP, the device
+ * 	driver is saying that it provided this DMA address, which the host
+ * 	controller driver should use instead of the transfer_buffer.
  * @transfer_buffer_length: How big is transfer_buffer.  The transfer may
  *	be broken up into chunks according to the current maximum packet
  *	size for the endpoint, which is a function of the configuration
@@ -789,6 +794,11 @@ typedef void (*usb_complete_t)(struct urb *);
  * @setup_packet: Only used for control transfers, this points to eight bytes
  *	of setup data.  Control transfers always start by sending this data
  *	to the device.  Then transfer_buffer is read or written, if needed.
+ *	(Not used when URB_NO_DMA_MAP is set.)
+ * @setup_dma: For control transfers with URB_NO_DMA_MAP set, the device
+ * 	driver has provided this DMA address for the setup packet.  The
+ * 	host controller driver should use instead of setup_buffer.
+ * 	If there is a data phase, its buffer is identified by transfer_dma.
  * @start_frame: Returns the initial frame for interrupt or isochronous
  *	transfers.
  * @number_of_packets: Lists the number of ISO transfer buffers.
@@ -811,6 +821,23 @@ typedef void (*usb_complete_t)(struct urb *);
  * are submitted using usb_submit_urb(), and pending requests may be canceled
  * using usb_unlink_urb().
  *
+ * Data Transfer Buffers:
+ *
+ * Normally drivers provide I/O buffers allocated with kmalloc() or otherwise
+ * taken from the general page pool.  That is provided by transfer_buffer
+ * (control requests also use setup_packet), and host controller drivers
+ * perform a dma mapping (and unmapping) for each buffer transferred.  Those
+ * mapping operations can be expensive on some platforms (such using a dma
+ * bounce buffer), although they're cheap on commodity x86 and ppc hardware.
+ *
+ * Alternatively, drivers may pass the URB_NO_DMA_MAP transfer flag, which
+ * tells the host controller driver that no such mapping is needed since
+ * the device driver is DMA-aware.  For example, they might allocate a DMA
+ * buffer with usb_buffer_alloc(), or call usb_buffer_map().
+ * When this transfer flag is provided, host controller drivers will use the
+ * dma addresses found in the transfer_dma and/or setup_dma fields rather than
+ * determing a dma address themselves.
+ *
  * Initialization:
  *
  * All URBs submitted must initialize dev, pipe,
@@ -818,10 +845,10 @@ typedef void (*usb_complete_t)(struct urb *);
  * The USB_ASYNC_UNLINK transfer flag affects later invocations of
  * the usb_unlink_urb() routine.
  *
- * All non-isochronous URBs must also initialize 
+ * All URBs must also initialize 
  * transfer_buffer and transfer_buffer_length.  They may provide the
  * URB_SHORT_NOT_OK transfer flag, indicating that short reads are
- * to be treated as errors.
+ * to be treated as errors; that flag is invalid for write requests.
  *
  * Bulk URBs may
  * use the USB_ZERO_PACKET transfer flag, indicating that bulk OUT transfers
@@ -896,10 +923,12 @@ struct urb
 	int status;			/* (return) non-ISO status */
 	unsigned int transfer_flags;	/* (in) URB_SHORT_NOT_OK | ...*/
 	void *transfer_buffer;		/* (in) associated data buffer */
+	dma_addr_t transfer_dma;	/* (in) dma addr for transfer_buffer */
 	int transfer_buffer_length;	/* (in) data buffer length */
 	int actual_length;		/* (return) actual transfer length */
 	int bandwidth;			/* bandwidth for INT/ISO request */
 	unsigned char *setup_packet;	/* (in) setup packet (control only) */
+	dma_addr_t setup_dma;		/* (in) dma addr for setup_packet */
 	int start_frame;		/* (modify) start frame (INT/ISO) */
 	int number_of_packets;		/* (in) number of ISO packets */
 	int interval;			/* (in) transfer interval (INT/ISO) */
@@ -910,6 +939,8 @@ struct urb
 	struct usb_iso_packet_descriptor iso_frame_desc[0];	/* (in) ISO ONLY */
 };
 
+/* -------------------------------------------------------------------------- */
+
 /**
  * usb_fill_control_urb - initializes a control urb
  * @urb: pointer to the urb to initialize.
@@ -1032,6 +1063,16 @@ extern struct urb *usb_get_urb(struct urb *urb);
 extern int usb_submit_urb(struct urb *urb, int mem_flags);
 extern int usb_unlink_urb(struct urb *urb);
 
+#define HAVE_USB_BUFFERS
+void *usb_buffer_alloc (struct usb_device *dev, size_t size,
+	int mem_flags, dma_addr_t *dma);
+void usb_buffer_free (struct usb_device *dev, size_t size,
+	void *addr, dma_addr_t dma);
+
+struct urb *usb_buffer_map (struct urb *urb);
+void usb_buffer_dmasync (struct urb *urb);
+void usb_buffer_unmap (struct urb *urb);
+
 /*-------------------------------------------------------------------*
  *                         SYNCHRONOUS CALL SUPPORT                  *
  *-------------------------------------------------------------------*/