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-rw-r--r--drivers/usb/host/pci-quirks.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/usb/host/pci-quirks.c b/drivers/usb/host/pci-quirks.c
index 20861650905..c225159ca3d 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;