USB: xhci: correctly enable interrupts

xhci has its own interrupt enabling routine, which will try to
use MSI-X/MSI if present. So the usb core shouldn't try to enable
legacy interrupts; on some machines the xhci legacy IRQ setting
is invalid.

v3: Be careful to not break XHCI_BROKEN_MSI workaround (by trenn)

Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Oliver Neukum <oneukum@suse.de>
Cc: Thomas Renninger <trenn@suse.de>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Frederik Himpe <fhimpe@vub.ac.be>
Cc: David Haerdeman <david@hardeman.nu>
Cc: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Reviewed-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index f1f01a834ba7..849470b18831 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -350,7 +350,7 @@ static int xhci_try_enable_msi(struct usb_hcd *hcd)
          * generate interrupts.  Don't even try to enable MSI.
          */
         if (xhci->quirks & XHCI_BROKEN_MSI)
-                return 0;
+                goto legacy_irq;
 
         /* unregister the legacy interrupt */
         if (hcd->irq)
@@ -371,6 +371,7 @@ static int xhci_try_enable_msi(struct usb_hcd *hcd)
                 return -EINVAL;
         }
 
+ legacy_irq:
         /* fall back to legacy interrupt*/
         ret = request_irq(pdev->irq, &usb_hcd_irq, IRQF_SHARED,
                         hcd->irq_descr, hcd);