3 files changed, 20 insertions, 2 deletions

diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
index c408e9f6a707..17541d09eabb 100644
--- a/drivers/usb/host/xhci-pci.c
+++ b/drivers/usb/host/xhci-pci.c
@@ -106,12 +106,22 @@ static int xhci_pci_setup(struct usb_hcd *hcd)
 
         /* Look for vendor-specific quirks */
         if (pdev->vendor == PCI_VENDOR_ID_FRESCO_LOGIC &&
-                        pdev->device == PCI_DEVICE_ID_FRESCO_LOGIC_PDK &&
-                        pdev->revision == 0x0) {
+                        pdev->device == PCI_DEVICE_ID_FRESCO_LOGIC_PDK) {
+                if (pdev->revision == 0x0) {
                         xhci->quirks |= XHCI_RESET_EP_QUIRK;
                         xhci_dbg(xhci, "QUIRK: Fresco Logic xHC needs configure"
                                         " endpoint cmd after reset endpoint\n");
+                }
+                /* Fresco Logic confirms: all revisions of this chip do not
+                 * support MSI, even though some of them claim to in their PCI
+                 * capabilities.
+                 */
+                xhci->quirks |= XHCI_BROKEN_MSI;
+                xhci_dbg(xhci, "QUIRK: Fresco Logic revision %u "
+                                "has broken MSI implementation\n",
+                                pdev->revision);
         }
+
         if (pdev->vendor == PCI_VENDOR_ID_NEC)
                 xhci->quirks |= XHCI_NEC_HOST;
 
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 66f3e41bba52..06e7023258d0 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -430,12 +430,19 @@ int xhci_run(struct usb_hcd *hcd)
                 free_irq(hcd->irq, hcd);
         hcd->irq = -1;
 
+        /* Some Fresco Logic host controllers advertise MSI, but fail to
+         * generate interrupts.  Don't even try to enable MSI.
+         */
+        if (xhci->quirks & XHCI_BROKEN_MSI)
+                goto legacy_irq;
+
         ret = xhci_setup_msix(xhci);
         if (ret)
                 /* fall back to msi*/
                 ret = xhci_setup_msi(xhci);
 
         if (ret) {
+legacy_irq:
                 /* fall back to legacy interrupt*/
                 ret = request_irq(pdev->irq, &usb_hcd_irq, IRQF_SHARED,
                                         hcd->irq_descr, hcd);
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index bbc1d9afb49c..7d1ea3bf5e1f 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1307,6 +1307,7 @@ struct xhci_hcd {
  * commands.
  */
 #define XHCI_EP_LIMIT_QUIRK     (1 << 5)
+#define XHCI_BROKEN_MSI         (1 << 6)
         unsigned int            num_active_eps;
         unsigned int            limit_active_eps;
         /* There are two roothubs to keep track of bus suspend info for */