usbcore: remove unused bandwith-related code

This patch (as841) removes from usbcore a couple of support routines
meant to help with bandwidth allocation.  With the changes to uhci-hcd
in the previous patch, these routines are no longer used anywhere.
Also removed is the CONFIG_USB_BANDWIDTH option; it no longer does
anything and is no longer needed since the HCDs now handle bandwidth
issues correctly.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/core/Kconfig

@@ -33,19 +33,6 @@ config USB_DEVICEFS
 
 	  Most users want to say Y here.
 
-config USB_BANDWIDTH
-	bool "Enforce USB bandwidth allocation (EXPERIMENTAL)"
-	depends on USB && EXPERIMENTAL
-	help
-	  If you say Y here, the USB subsystem enforces USB bandwidth
-	  allocation and will prevent some device opens from succeeding
-	  if they would cause USB bandwidth usage to go above 90% of
-	  the bus bandwidth.
-
-	  If you say N here, these conditions will cause warning messages
-	  about USB bandwidth usage to be logged and some devices or
-	  drivers may not work correctly.
-
 config USB_DYNAMIC_MINORS
 	bool "Dynamic USB minor allocation (EXPERIMENTAL)"
 	depends on USB && EXPERIMENTAL

drivers/usb/core/hcd.c

@@ -45,8 +45,6 @@
 #include "hub.h"
 
 
-// #define USB_BANDWIDTH_MESSAGES
-
 /*-------------------------------------------------------------------------*/
 
 /*
@@ -891,136 +889,6 @@ long usb_calc_bus_time (int speed, int is_input, int isoc, int bytecount)
 }
 EXPORT_SYMBOL (usb_calc_bus_time);
 
-/*
- * usb_check_bandwidth():
- *
- * old_alloc is from host_controller->bandwidth_allocated in microseconds;
- * bustime is from calc_bus_time(), but converted to microseconds.
- *
- * returns <bustime in us> if successful,
- * or -ENOSPC if bandwidth request fails.
- *
- * FIXME:
- * This initial implementation does not use Endpoint.bInterval
- * in managing bandwidth allocation.
- * It probably needs to be expanded to use Endpoint.bInterval.
- * This can be done as a later enhancement (correction).
- *
- * This will also probably require some kind of
- * frame allocation tracking...meaning, for example,
- * that if multiple drivers request interrupts every 10 USB frames,
- * they don't all have to be allocated at
- * frame numbers N, N+10, N+20, etc.  Some of them could be at
- * N+11, N+21, N+31, etc., and others at
- * N+12, N+22, N+32, etc.
- *
- * Similarly for isochronous transfers...
- *
- * Individual HCDs can schedule more directly ... this logic
- * is not correct for high speed transfers.
- */
-int usb_check_bandwidth (struct usb_device *dev, struct urb *urb)
-{
-	unsigned int	pipe = urb->pipe;
-	long		bustime;
-	int		is_in = usb_pipein (pipe);
-	int		is_iso = usb_pipeisoc (pipe);
-	int		old_alloc = dev->bus->bandwidth_allocated;
-	int		new_alloc;
-
-
-	bustime = NS_TO_US (usb_calc_bus_time (dev->speed, is_in, is_iso,
-			usb_maxpacket (dev, pipe, !is_in)));
-	if (is_iso)
-		bustime /= urb->number_of_packets;
-
-	new_alloc = old_alloc + (int) bustime;
-	if (new_alloc > FRAME_TIME_MAX_USECS_ALLOC) {
-#ifdef	DEBUG
-		char	*mode = 
-#ifdef CONFIG_USB_BANDWIDTH
-			"";
-#else
-			"would have ";
-#endif
-		dev_dbg (&dev->dev, "usb_check_bandwidth %sFAILED: %d + %ld = %d usec\n",
-			mode, old_alloc, bustime, new_alloc);
-#endif
-#ifdef CONFIG_USB_BANDWIDTH
-		bustime = -ENOSPC;	/* report error */
-#endif
-	}
-
-	return bustime;
-}
-EXPORT_SYMBOL (usb_check_bandwidth);
-
-
-/**
- * usb_claim_bandwidth - records bandwidth for a periodic transfer
- * @dev: source/target of request
- * @urb: request (urb->dev == dev)
- * @bustime: bandwidth consumed, in (average) microseconds per frame
- * @isoc: true iff the request is isochronous
- *
- * Bus bandwidth reservations are recorded purely for diagnostic purposes.
- * HCDs are expected not to overcommit periodic bandwidth, and to record such
- * reservations whenever endpoints are added to the periodic schedule.
- *
- * FIXME averaging per-frame is suboptimal.  Better to sum over the HCD's
- * entire periodic schedule ... 32 frames for OHCI, 1024 for UHCI, settable
- * for EHCI (256/512/1024 frames, default 1024) and have the bus expose how
- * large its periodic schedule is.
- */
-void usb_claim_bandwidth (struct usb_device *dev, struct urb *urb, int bustime, int isoc)
-{
-	dev->bus->bandwidth_allocated += bustime;
-	if (isoc)
-		dev->bus->bandwidth_isoc_reqs++;
-	else
-		dev->bus->bandwidth_int_reqs++;
-	urb->bandwidth = bustime;
-
-#ifdef USB_BANDWIDTH_MESSAGES
-	dev_dbg (&dev->dev, "bandwidth alloc increased by %d (%s) to %d for %d requesters\n",
-		bustime,
-		isoc ? "ISOC" : "INTR",
-		dev->bus->bandwidth_allocated,
-		dev->bus->bandwidth_int_reqs + dev->bus->bandwidth_isoc_reqs);
-#endif
-}
-EXPORT_SYMBOL (usb_claim_bandwidth);
-
-
-/**
- * usb_release_bandwidth - reverses effect of usb_claim_bandwidth()
- * @dev: source/target of request
- * @urb: request (urb->dev == dev)
- * @isoc: true iff the request is isochronous
- *
- * This records that previously allocated bandwidth has been released.
- * Bandwidth is released when endpoints are removed from the host controller's
- * periodic schedule.
- */
-void usb_release_bandwidth (struct usb_device *dev, struct urb *urb, int isoc)
-{
-	dev->bus->bandwidth_allocated -= urb->bandwidth;
-	if (isoc)
-		dev->bus->bandwidth_isoc_reqs--;
-	else
-		dev->bus->bandwidth_int_reqs--;
-
-#ifdef USB_BANDWIDTH_MESSAGES
-	dev_dbg (&dev->dev, "bandwidth alloc reduced by %d (%s) to %d for %d requesters\n",
-		urb->bandwidth,
-		isoc ? "ISOC" : "INTR",
-		dev->bus->bandwidth_allocated,
-		dev->bus->bandwidth_int_reqs + dev->bus->bandwidth_isoc_reqs);
-#endif
-	urb->bandwidth = 0;
-}
-EXPORT_SYMBOL (usb_release_bandwidth);
-
 
 /*-------------------------------------------------------------------------*/
 
@@ -1034,11 +902,6 @@ static void urb_unlink (struct urb *urb)
 {
 	unsigned long		flags;
 
-	/* Release any periodic transfer bandwidth */
-	if (urb->bandwidth)
-		usb_release_bandwidth (urb->dev, urb,
-			usb_pipeisoc (urb->pipe));
-
 	/* clear all state linking urb to this dev (and hcd) */
 
 	spin_lock_irqsave (&hcd_data_lock, flags);

drivers/usb/core/hcd.h

@@ -308,10 +308,6 @@ extern void usb_destroy_configuration(struct usb_device *dev);
 #define NS_TO_US(ns)	((ns + 500L) / 1000L)
 			/* convert & round nanoseconds to microseconds */
 
-extern void usb_claim_bandwidth (struct usb_device *dev, struct urb *urb,
-		int bustime, int isoc);
-extern void usb_release_bandwidth (struct usb_device *dev, struct urb *urb,
-		int isoc);
 
 /*
  * Full/low speed bandwidth allocation constants/support.
@@ -324,8 +320,6 @@ extern void usb_release_bandwidth (struct usb_device *dev, struct urb *urb,
 #define FRAME_TIME_MAX_BITS_ALLOC	(90L * FRAME_TIME_BITS / 100L)
 #define FRAME_TIME_MAX_USECS_ALLOC	(90L * FRAME_TIME_USECS / 100L)
 
-extern int usb_check_bandwidth (struct usb_device *dev, struct urb *urb);
-
 /*
  * Ceiling [nano/micro]seconds (typical) for that many bytes at high speed
  * ISO is a bit less, no ACK ... from USB 2.0 spec, 5.11.3 (and needed

drivers/usb/core/urb.c

@@ -235,7 +235,6 @@ int usb_submit_urb(struct urb *urb, gfp_t mem_flags)
 
 	urb->status = -EINPROGRESS;
 	urb->actual_length = 0;
-	urb->bandwidth = 0;
 
 	/* Lots of sanity checks, so HCDs can rely on clean data
 	 * and don't need to duplicate tests

include/linux/usb.h

@@ -1110,7 +1110,6 @@ struct urb
 	struct kref kref;		/* reference count of the URB */
 	spinlock_t lock;		/* lock for the URB */
 	void *hcpriv;			/* private data for host controller */
-	int bandwidth;			/* bandwidth for INT/ISO request */
 	atomic_t use_count;		/* concurrent submissions counter */
 	u8 reject;			/* submissions will fail */