Merge branch 'stable-3.2' into pandora-3.2

[pandora-kernel.git] / drivers / usb / host / xhci-hub.c

diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
index 13bb316..d89b72c 100644 (file)
--- a/drivers/usb/host/xhci-hub.c
+++ b/drivers/usb/host/xhci-hub.c
@@ -1036,6 +1036,35 @@ int xhci_bus_suspend(struct usb_hcd *hcd)
        return 0;
 }
 
+/*
+ * Workaround for missing Cold Attach Status (CAS) if device re-plugged in S3.
+ * warm reset a USB3 device stuck in polling or compliance mode after resume.
+ * See Intel 100/c230 series PCH specification update Doc #332692-006 Errata #8
+ */
+static bool xhci_port_missing_cas_quirk(int port_index,
+                                            __le32 __iomem **port_array)
+{
+       u32 portsc;
+
+       portsc = readl(port_array[port_index]);
+
+       /* if any of these are set we are not stuck */
+       if (portsc & (PORT_CONNECT | PORT_CAS))
+               return false;
+
+       if (((portsc & PORT_PLS_MASK) != XDEV_POLLING) &&
+           ((portsc & PORT_PLS_MASK) != XDEV_COMP_MODE))
+               return false;
+
+       /* clear wakeup/change bits, and do a warm port reset */
+       portsc &= ~(PORT_RWC_BITS | PORT_CEC | PORT_WAKE_BITS);
+       portsc |= PORT_WR;
+       writel(portsc, port_array[port_index]);
+       /* flush write */
+       readl(port_array[port_index]);
+       return true;
+}
+
 int xhci_bus_resume(struct usb_hcd *hcd)
 {
        struct xhci_hcd *xhci = hcd_to_xhci(hcd);
@@ -1070,6 +1099,14 @@ int xhci_bus_resume(struct usb_hcd *hcd)
                int slot_id;
 
                temp = xhci_readl(xhci, port_array[port_index]);
+
+               /* warm reset CAS limited ports stuck in polling/compliance */
+               if ((xhci->quirks & XHCI_MISSING_CAS) &&
+                   (hcd->speed >= HCD_USB3) &&
+                   xhci_port_missing_cas_quirk(port_index, port_array)) {
+                       xhci_dbg(xhci, "reset stuck port %d\n", port_index);
+                       continue;
+               }
                if (DEV_SUPERSPEED(temp))
                        temp &= ~(PORT_RWC_BITS | PORT_CEC | PORT_WAKE_BITS);
                else