[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>

1 files changed, 96 insertions, 46 deletions

diff --git a/drivers/usb/host/pci-quirks.c b/drivers/usb/host/pci-quirks.c
index 49f7381a6fd3..f7411ca48835 100644
--- a/drivers/usb/host/pci-quirks.c
+++ b/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;
+        /* 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);
 
-        for (i = 0; i < PCI_ROM_RESOURCE; i++)
-                if ((pci_resource_flags(pdev, i) & IORESOURCE_IO)) {
-                        base = pci_resource_start(pdev, i);
-                        break;
-                }
+        /* 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);
 
-        if (!base)
-                return;
+/*
+ * 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.
+ */
+int uhci_check_and_reset_hc(struct pci_dev *pdev, unsigned long base)
+{
+        u16 legsup;
+        unsigned int cmd, intr;
 
         /*
-         * stop controller
+         * 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.
          */
-        sts = inw(base + UHCI_USBSTS);
-        val = inw(base + UHCI_USBCMD);
-        val &= ~(u16)(UHCI_USBCMD_RUN | UHCI_USBCMD_CONFIGURE);
-        outw(val, base + UHCI_USBCMD);
+        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;
+        }
 
-        /*
-         * wait while it stops if it was running
-         */
-        if ((sts & UHCI_USBSTS_HALTED) == 0)
-        {
-                wait_time = 1000;
-                delta = 100;
+        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;
+        }
 
-                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);
+        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;
 
-        /*
-         * 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);
+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)