[PATCH] USB: fix EHCI early handoff issues

This moves the previously widely-used ehci-pci.c BIOS handoff
code into the pci-quirks.c file, replacing the less widely used
"early handoff" version that seems to cause problems lately.

One notable change:  the "early handoff" version always enabled
an SMI IRQ ... and did so even if the pre-Linux code said it was
not using EHCI (and not expecting EHCI SMIs).  Looks like a goof
in a workaround for some unknown BIOS version.

This merged version only forcibly enables those IRQs when pre-Linux
code says it's using EHCI.  And now it always forces them off "just
in case".

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 68 insertions, 38 deletions

diff --git a/drivers/usb/host/pci-quirks.c b/drivers/usb/host/pci-quirks.c
index 3ef2c0cdf1db..e9e5bc178cef 100644
--- a/drivers/usb/host/pci-quirks.c
+++ b/drivers/usb/host/pci-quirks.c
@@ -190,7 +190,7 @@ static void __devinit quirk_usb_handoff_ohci(struct pci_dev *pdev)
                         msleep(10);
                 }
                 if (wait_time <= 0)
-                        printk(KERN_WARNING "%s %s: early BIOS handoff "
+                        printk(KERN_WARNING "%s %s: BIOS handoff "
                                         "failed (BIOS bug ?)\n",
                                         pdev->dev.bus_id, "OHCI");
 
@@ -212,8 +212,9 @@ static void __devinit quirk_usb_disable_ehci(struct pci_dev *pdev)
 {
         int wait_time, delta;
         void __iomem *base, *op_reg_base;
-        u32 hcc_params, val, temp;
-        u8 cap_length;
+        u32     hcc_params, val;
+        u8      offset, cap_length;
+        int     count = 256/4;
 
         if (!mmio_resource_enabled(pdev, 0))
                 return;
@@ -224,51 +225,80 @@ static void __devinit quirk_usb_disable_ehci(struct pci_dev *pdev)
 
         cap_length = readb(base);
         op_reg_base = base + cap_length;
+
+        /* EHCI 0.96 and later may have "extended capabilities"
+         * spec section 5.1 explains the bios handoff, e.g. for
+         * booting from USB disk or using a usb keyboard
+         */
         hcc_params = readl(base + EHCI_HCC_PARAMS);
-        hcc_params = (hcc_params >> 8) & 0xff;
-        if (hcc_params) {
-                pci_read_config_dword(pdev,
-                                        hcc_params + EHCI_USBLEGSUP,
-                                        &val);
-                if (((val & 0xff) == 1) && (val & EHCI_USBLEGSUP_BIOS)) {
-                        /*
-                         * Ok, BIOS is in smm mode, try to hand off...
+        offset = (hcc_params >> 8) & 0xff;
+        while (offset && count--) {
+                u32             cap;
+                int             msec;
+
+                pci_read_config_dword(pdev, offset, &cap);
+                switch (cap & 0xff) {
+                case 1:                 /* BIOS/SMM/... handoff support */
+                        if ((cap & EHCI_USBLEGSUP_BIOS)) {
+                                pr_debug("%s %s: BIOS handoff\n",
+                                                pdev->dev.bus_id, "EHCI");
+
+                                /* BIOS workaround (?): be sure the
+                                 * pre-Linux code receives the SMI
+                                 */
+                                pci_read_config_dword(pdev,
+                                                offset + EHCI_USBLEGCTLSTS,
+                                                &val);
+                                pci_write_config_dword(pdev,
+                                                offset + EHCI_USBLEGCTLSTS,
+                                                val | EHCI_USBLEGCTLSTS_SOOE);
+                        }
+
+                        /* always say Linux will own the hardware
+                         * by setting EHCI_USBLEGSUP_OS.
                          */
-                        pci_read_config_dword(pdev,
-                                                hcc_params + EHCI_USBLEGCTLSTS,
-                                                &temp);
-                        pci_write_config_dword(pdev,
-                                                hcc_params + EHCI_USBLEGCTLSTS,
-                                                temp | EHCI_USBLEGCTLSTS_SOOE);
-                        val |= EHCI_USBLEGSUP_OS;
-                        pci_write_config_dword(pdev,
-                                                hcc_params + EHCI_USBLEGSUP,
-                                                val);
+                        pci_write_config_byte(pdev, offset + 3, 1);
 
-                        wait_time = 500;
-                        do {
+                        /* if boot firmware now owns EHCI, spin till
+                         * it hands it over.
+                         */
+                        msec = 5000;
+                        while ((cap & EHCI_USBLEGSUP_BIOS) && (msec > 0)) {
                                 msleep(10);
-                                wait_time -= 10;
-                                pci_read_config_dword(pdev,
-                                                hcc_params + EHCI_USBLEGSUP,
-                                                &val);
-                        } while (wait_time && (val & EHCI_USBLEGSUP_BIOS));
-                        if (!wait_time) {
-                                /*
-                                 * well, possibly buggy BIOS...
+                                msec -= 10;
+                                pci_read_config_dword(pdev, offset, &cap);
+                        }
+
+                        if (cap & EHCI_USBLEGSUP_BIOS) {
+                                /* well, possibly buggy BIOS... try to shut
+                                 * it down, and hope nothing goes too wrong
                                  */
-                                printk(KERN_WARNING "%s %s: early BIOS handoff "
+                                printk(KERN_WARNING "%s %s: BIOS handoff "
                                                 "failed (BIOS bug ?)\n",
                                         pdev->dev.bus_id, "EHCI");
-                                pci_write_config_dword(pdev,
-                                                hcc_params + EHCI_USBLEGSUP,
-                                                EHCI_USBLEGSUP_OS);
-                                pci_write_config_dword(pdev,
-                                                hcc_params + EHCI_USBLEGCTLSTS,
-                                                0);
+                                pci_write_config_byte(pdev, offset + 2, 0);
                         }
+
+                        /* just in case, always disable EHCI SMIs */
+                        pci_write_config_dword(pdev,
+                                        offset + EHCI_USBLEGCTLSTS,
+                                        0);
+                        break;
+                case 0:                 /* illegal reserved capability */
+                        cap = 0;
+                        /* FALLTHROUGH */
+                default:
+                        printk(KERN_WARNING "%s %s: unrecognized "
+                                        "capability %02x\n",
+                                        pdev->dev.bus_id, "EHCI",
+                                        cap & 0xff);
+                        break;
                 }
+                offset = (cap >> 8) & 0xff;
         }
+        if (!count)
+                printk(KERN_DEBUG "%s %s: capability loop?\n",
+                                pdev->dev.bus_id, "EHCI");
 
         /*
          * halt EHCI & disable its interrupts in any case