EHCI: fix problem with BIOS handoff

This patch (as882) fixes a problem with the EHCI BIOS handoff.  On my
machine, the BIOS configures the controller and the handoff fails,
leaving the controller configured.  During resume-from-disk, this
confuses ehci-hcd into thinking that the controller has not been
tampered with.

The problem is fixed by turning off the Configured Flag whenever a
BIOS handoff is attempted, whether it succeeds or not.

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>

diff --git a/drivers/usb/host/pci-quirks.c b/drivers/usb/host/pci-quirks.c
index 20861650905e63606955056b5169581a0b92463c..c225159ca3d346759a33b73b49743d64914ba778 100644 (file)
--- a/drivers/usb/host/pci-quirks.c
+++ b/drivers/usb/host/pci-quirks.c
@@ -44,6 +44,7 @@
 #define EHCI_USBSTS            4               /* status register */
 #define EHCI_USBSTS_HALTED     (1 << 12)       /* HCHalted bit */
 #define EHCI_USBINTR           8               /* interrupt register */
+#define EHCI_CONFIGFLAG                0x40            /* configured flag register */
 #define EHCI_USBLEGSUP         0               /* legacy support register */
 #define EHCI_USBLEGSUP_BIOS    (1 << 16)       /* BIOS semaphore */
 #define EHCI_USBLEGSUP_OS      (1 << 24)       /* OS semaphore */
@@ -216,6 +217,7 @@ static void __devinit quirk_usb_disable_ehci(struct pci_dev *pdev)
        u32     hcc_params, val;
        u8      offset, cap_length;
        int     count = 256/4;
+       int     tried_handoff = 0;
 
        if (!mmio_resource_enabled(pdev, 0))
                return;
@@ -273,6 +275,7 @@ static void __devinit quirk_usb_disable_ehci(struct pci_dev *pdev)
                         */
                        msec = 5000;
                        while ((cap & EHCI_USBLEGSUP_BIOS) && (msec > 0)) {
+                               tried_handoff = 1;
                                msleep(10);
                                msec -= 10;
                                pci_read_config_dword(pdev, offset, &cap);
@@ -292,6 +295,12 @@ static void __devinit quirk_usb_disable_ehci(struct pci_dev *pdev)
                        pci_write_config_dword(pdev,
                                        offset + EHCI_USBLEGCTLSTS,
                                        0);
+
+                       /* If the BIOS ever owned the controller then we
+                        * can't expect any power sessions to remain intact.
+                        */
+                       if (tried_handoff)
+                               writel(0, op_reg_base + EHCI_CONFIGFLAG);
                        break;
                case 0:                 /* illegal reserved capability */
                        cap = 0;