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>

2 files changed, 16 insertions, 10 deletions

diff --git a/drivers/usb/core/hcd-pci.c b/drivers/usb/core/hcd-pci.c
index 622b4a48e732..2b487d4797bd 100644
--- a/drivers/usb/core/hcd-pci.c
+++ b/drivers/usb/core/hcd-pci.c
@@ -173,6 +173,7 @@ int usb_hcd_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
         struct hc_driver        *driver;
         struct usb_hcd          *hcd;
         int                     retval;
+        int                     hcd_irq = 0;
 
         if (usb_disabled())
                 return -ENODEV;
@@ -187,15 +188,19 @@ int usb_hcd_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
                 return -ENODEV;
         dev->current_state = PCI_D0;
 
-        /* The xHCI driver supports MSI and MSI-X,
-         * so don't fail if the BIOS doesn't provide a legacy IRQ.
+        /*
+         * The xHCI driver has its own irq management
+         * make sure irq setup is not touched for xhci in generic hcd code
          */
-        if (!dev->irq && (driver->flags & HCD_MASK) != HCD_USB3) {
-                dev_err(&dev->dev,
-                        "Found HC with no IRQ.  Check BIOS/PCI %s setup!\n",
-                        pci_name(dev));
-                retval = -ENODEV;
-                goto disable_pci;
+        if ((driver->flags & HCD_MASK) != HCD_USB3) {
+                if (!dev->irq) {
+                        dev_err(&dev->dev,
+                        "Found HC with no IRQ. Check BIOS/PCI %s setup!\n",
+                                pci_name(dev));
+                        retval = -ENODEV;
+                        goto disable_pci;
+                }
+                hcd_irq = dev->irq;
         }
 
         hcd = usb_create_hcd(driver, &dev->dev, pci_name(dev));
@@ -245,7 +250,7 @@ int usb_hcd_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
 
         pci_set_master(dev);
 
-        retval = usb_add_hcd(hcd, dev->irq, IRQF_SHARED);
+        retval = usb_add_hcd(hcd, hcd_irq, IRQF_SHARED);
         if (retval != 0)
                 goto unmap_registers;
         set_hs_companion(dev, hcd);
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);