1 files changed, 9 insertions, 0 deletions

diff --git a/drivers/usb/host/pci-quirks.c b/drivers/usb/host/pci-quirks.c
index 20861650905e..c225159ca3d3 100644
--- 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;