[PATCH] UHCI: unify BIOS handoff and driver reset code

This patch (as574) updates the PCI BIOS usb-handoff code for UHCI
controllers, making it work like the reset routines in uhci-hcd.  This
allows uhci-hcd to drop its own routines in favor of the new ones
(code-sharing).

Once the patch is merged we can turn the usb-handoff option on
permanently, as far as UHCI is concerned.  OHCI and EHCI may still have
some issues.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/host/pci-quirks.c

@@ -9,6 +9,12 @@
  */
 
 #include <linux/config.h>
+#ifdef CONFIG_USB_DEBUG
+#define DEBUG
+#else
+#undef DEBUG
+#endif
+
 #include <linux/types.h>
 #include <linux/kernel.h>
 #include <linux/pci.h>
@@ -46,13 +52,14 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL,	PCI_DEVICE_ID_INTEL_82371AB_2,	qui
 
 #define UHCI_USBLEGSUP		0xc0		/* legacy support */
 #define UHCI_USBCMD		0		/* command register */
-#define UHCI_USBSTS		2		/* status register */
 #define UHCI_USBINTR		4		/* interrupt register */
-#define UHCI_USBLEGSUP_DEFAULT	0x2000		/* only PIRQ enable set */
-#define UHCI_USBCMD_RUN		(1 << 0)	/* RUN/STOP bit */
-#define UHCI_USBCMD_GRESET	(1 << 2)	/* Global reset */
-#define UHCI_USBCMD_CONFIGURE	(1 << 6)	/* config semaphore */
-#define UHCI_USBSTS_HALTED	(1 << 5)	/* HCHalted bit */
+#define UHCI_USBLEGSUP_RWC	0x8f00		/* the R/WC bits */
+#define UHCI_USBLEGSUP_RO	0x5040		/* R/O and reserved bits */
+#define UHCI_USBCMD_RUN		0x0001		/* RUN/STOP bit */
+#define UHCI_USBCMD_HCRESET	0x0002		/* Host Controller reset */
+#define UHCI_USBCMD_EGSM	0x0008		/* Global Suspend Mode */
+#define UHCI_USBCMD_CONFIGURE	0x0040		/* Config Flag */
+#define UHCI_USBINTR_RESUME	0x0002		/* Resume interrupt enable */
 
 #define OHCI_CONTROL		0x04
 #define OHCI_CMDSTATUS		0x08
@@ -84,57 +91,100 @@ static int __init usb_handoff_early(char *str)
 }
 __setup("usb-handoff", usb_handoff_early);
 
-static void __devinit quirk_usb_handoff_uhci(struct pci_dev *pdev)
+/*
+ * Make sure the controller is completely inactive, unable to
+ * generate interrupts or do DMA.
+ */
+void uhci_reset_hc(struct pci_dev *pdev, unsigned long base)
 {
-	unsigned long base = 0;
-	int wait_time, delta;
-	u16 val, sts;
-	int i;
-
-	for (i = 0; i < PCI_ROM_RESOURCE; i++)
-		if ((pci_resource_flags(pdev, i) & IORESOURCE_IO)) {
-			base = pci_resource_start(pdev, i);
-			break;
-		}
+	/* Turn off PIRQ enable and SMI enable.  (This also turns off the
+	 * BIOS's USB Legacy Support.)  Turn off all the R/WC bits too.
+	 */
+	pci_write_config_word(pdev, UHCI_USBLEGSUP, UHCI_USBLEGSUP_RWC);
 
-	if (!base)
-		return;
+	/* Reset the HC - this will force us to get a
+	 * new notification of any already connected
+	 * ports due to the virtual disconnect that it
+	 * implies.
+	 */
+	outw(UHCI_USBCMD_HCRESET, base + UHCI_USBCMD);
+	mb();
+	udelay(5);
+	if (inw(base + UHCI_USBCMD) & UHCI_USBCMD_HCRESET)
+		dev_warn(&pdev->dev, "HCRESET not completed yet!\n");
+
+	/* Just to be safe, disable interrupt requests and
+	 * make sure the controller is stopped.
+	 */
+	outw(0, base + UHCI_USBINTR);
+	outw(0, base + UHCI_USBCMD);
+}
+EXPORT_SYMBOL_GPL(uhci_reset_hc);
 
-	/*
-	 * stop controller
+/*
+ * Initialize a controller that was newly discovered or has just been
+ * resumed.  In either case we can't be sure of its previous state.
+ *
+ * Returns: 1 if the controller was reset, 0 otherwise.
  */
-	sts = inw(base + UHCI_USBSTS);
-	val = inw(base + UHCI_USBCMD);
-	val &= ~(u16)(UHCI_USBCMD_RUN | UHCI_USBCMD_CONFIGURE);
-	outw(val, base + UHCI_USBCMD);
+int uhci_check_and_reset_hc(struct pci_dev *pdev, unsigned long base)
+{
+	u16 legsup;
+	unsigned int cmd, intr;
 
 	/*
-	 * wait while it stops if it was running
+	 * When restarting a suspended controller, we expect all the
+	 * settings to be the same as we left them:
+	 *
+	 *	PIRQ and SMI disabled, no R/W bits set in USBLEGSUP;
+	 *	Controller is stopped and configured with EGSM set;
+	 *	No interrupts enabled except possibly Resume Detect.
+	 *
+	 * If any of these conditions are violated we do a complete reset.
 	 */
-	if ((sts & UHCI_USBSTS_HALTED) == 0)
-	{
-		wait_time = 1000;
-		delta = 100;
+	pci_read_config_word(pdev, UHCI_USBLEGSUP, &legsup);
+	if (legsup & ~(UHCI_USBLEGSUP_RO | UHCI_USBLEGSUP_RWC)) {
+		dev_dbg(&pdev->dev, "%s: legsup = 0x%04x\n",
+				__FUNCTION__, legsup);
+		goto reset_needed;
+	}
 
-		do {
-			outw(0x1f, base + UHCI_USBSTS);
-			udelay(delta);
-			wait_time -= delta;
-			val = inw(base + UHCI_USBSTS);
-			if (val & UHCI_USBSTS_HALTED)
-				break;
-		} while (wait_time > 0);
+	cmd = inw(base + UHCI_USBCMD);
+	if ((cmd & UHCI_USBCMD_RUN) || !(cmd & UHCI_USBCMD_CONFIGURE) ||
+			!(cmd & UHCI_USBCMD_EGSM)) {
+		dev_dbg(&pdev->dev, "%s: cmd = 0x%04x\n",
+				__FUNCTION__, cmd);
+		goto reset_needed;
 	}
 
-	/*
-	 * disable interrupts & legacy support
-	 */
-	outw(0, base + UHCI_USBINTR);
-	outw(0x1f, base + UHCI_USBSTS);
-	pci_read_config_word(pdev, UHCI_USBLEGSUP, &val);
-	if (val & 0xbf)
-		pci_write_config_word(pdev, UHCI_USBLEGSUP, UHCI_USBLEGSUP_DEFAULT);
+	intr = inw(base + UHCI_USBINTR);
+	if (intr & (~UHCI_USBINTR_RESUME)) {
+		dev_dbg(&pdev->dev, "%s: intr = 0x%04x\n",
+				__FUNCTION__, intr);
+		goto reset_needed;
+	}
+	return 0;
+
+reset_needed:
+	dev_dbg(&pdev->dev, "Performing full reset\n");
+	uhci_reset_hc(pdev, base);
+	return 1;
+}
+EXPORT_SYMBOL_GPL(uhci_check_and_reset_hc);
+
+static void __devinit quirk_usb_handoff_uhci(struct pci_dev *pdev)
+{
+	unsigned long base = 0;
+	int i;
+
+	for (i = 0; i < PCI_ROM_RESOURCE; i++)
+		if ((pci_resource_flags(pdev, i) & IORESOURCE_IO)) {
+			base = pci_resource_start(pdev, i);
+			break;
+		}
 
+	if (base)
+		uhci_check_and_reset_hc(pdev, base);
 }
 
 static void __devinit quirk_usb_handoff_ohci(struct pci_dev *pdev)

drivers/usb/host/uhci-hcd.c

@@ -101,37 +101,16 @@ static void uhci_get_current_frame_number(struct uhci_hcd *uhci);
 #include "uhci-q.c"
 #include "uhci-hub.c"
 
+extern void uhci_reset_hc(struct pci_dev *pdev, unsigned long base);
+extern int uhci_check_and_reset_hc(struct pci_dev *pdev, unsigned long base);
+
 /*
- * Make sure the controller is completely inactive, unable to
- * generate interrupts or do DMA.
+ * Finish up a host controller reset and update the recorded state.
  */
-static void reset_hc(struct uhci_hcd *uhci)
+static void finish_reset(struct uhci_hcd *uhci)
 {
 	int port;
 
-	/* Turn off PIRQ enable and SMI enable.  (This also turns off the
-	 * BIOS's USB Legacy Support.)  Turn off all the R/WC bits too.
-	 */
-	pci_write_config_word(to_pci_dev(uhci_dev(uhci)), USBLEGSUP,
-			USBLEGSUP_RWC);
-
-	/* Reset the HC - this will force us to get a
-	 * new notification of any already connected
-	 * ports due to the virtual disconnect that it
-	 * implies.
-	 */
-	outw(USBCMD_HCRESET, uhci->io_addr + USBCMD);
-	mb();
-	udelay(5);
-	if (inw(uhci->io_addr + USBCMD) & USBCMD_HCRESET)
-		dev_warn(uhci_dev(uhci), "HCRESET not completed yet!\n");
-
-	/* Just to be safe, disable interrupt requests and
-	 * make sure the controller is stopped.
-	 */
-	outw(0, uhci->io_addr + USBINTR);
-	outw(0, uhci->io_addr + USBCMD);
-
 	/* HCRESET doesn't affect the Suspend, Reset, and Resume Detect
 	 * bits in the port status and control registers.
 	 * We have to clear them by hand.
@@ -153,7 +132,8 @@ static void reset_hc(struct uhci_hcd *uhci)
  */
 static void hc_died(struct uhci_hcd *uhci)
 {
-	reset_hc(uhci);
+	uhci_reset_hc(to_pci_dev(uhci_dev(uhci)), uhci->io_addr);
+	finish_reset(uhci);
 	uhci->hc_inaccessible = 1;
 }
 
@@ -163,44 +143,8 @@ static void hc_died(struct uhci_hcd *uhci)
  */
 static void check_and_reset_hc(struct uhci_hcd *uhci)
 {
-	u16 legsup;
-	unsigned int cmd, intr;
-
-	/*
-	 * When restarting a suspended controller, we expect all the
-	 * settings to be the same as we left them:
-	 *
-	 *	PIRQ and SMI disabled, no R/W bits set in USBLEGSUP;
-	 *	Controller is stopped and configured with EGSM set;
-	 *	No interrupts enabled except possibly Resume Detect.
-	 *
-	 * If any of these conditions are violated we do a complete reset.
-	 */
-	pci_read_config_word(to_pci_dev(uhci_dev(uhci)), USBLEGSUP, &legsup);
-	if (legsup & ~(USBLEGSUP_RO | USBLEGSUP_RWC)) {
-		dev_dbg(uhci_dev(uhci), "%s: legsup = 0x%04x\n",
-				__FUNCTION__, legsup);
-		goto reset_needed;
-	}
-
-	cmd = inw(uhci->io_addr + USBCMD);
-	if ((cmd & USBCMD_RS) || !(cmd & USBCMD_CF) || !(cmd & USBCMD_EGSM)) {
-		dev_dbg(uhci_dev(uhci), "%s: cmd = 0x%04x\n",
-				__FUNCTION__, cmd);
-		goto reset_needed;
-	}
-
-	intr = inw(uhci->io_addr + USBINTR);
-	if (intr & (~USBINTR_RESUME)) {
-		dev_dbg(uhci_dev(uhci), "%s: intr = 0x%04x\n",
-				__FUNCTION__, intr);
-		goto reset_needed;
-	}
-	return;
-
-reset_needed:
-	dev_dbg(uhci_dev(uhci), "Performing full reset\n");
-	reset_hc(uhci);
+	if (uhci_check_and_reset_hc(to_pci_dev(uhci_dev(uhci)), uhci->io_addr))
+		finish_reset(uhci);
 }
 
 /*
@@ -714,7 +658,7 @@ static void uhci_stop(struct usb_hcd *hcd)
 
 	spin_lock_irq(&uhci->lock);
 	if (!uhci->hc_inaccessible)
-		reset_hc(uhci);
+		hc_died(uhci);
 	uhci_scan_schedule(uhci, NULL);
 	spin_unlock_irq(&uhci->lock);