usb/xhci: group MSI interrupt registration into its own function

This patch moves the complete MSI/MSI-X/Legacy dance into its own
function. There is however one difference: If the XHCI_BROKEN_MSI flag
is set then we don't free and register the irq, we simply return.
This is preparation for later PCI decouple.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 7bf8677..583a3e3 100644 (file)
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -397,6 +397,45 @@ static int xhci_run_finished(struct xhci_hcd *xhci)
        return 0;
 }
 
+static int xhci_try_enable_msi(struct usb_hcd *hcd)
+{
+       struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+       struct pci_dev  *pdev = to_pci_dev(xhci_to_hcd(xhci)->self.controller);
+       int ret;
+
+       /*
+        * 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)
+               return 0;
+
+       /* unregister the legacy interrupt */
+       if (hcd->irq)
+               free_irq(hcd->irq, hcd);
+       hcd->irq = -1;
+
+       ret = xhci_setup_msix(xhci);
+       if (ret)
+               /* fall back to msi*/
+               ret = xhci_setup_msi(xhci);
+
+       if (!ret)
+               /* hcd->irq is -1, we have MSI */
+               return 0;
+
+       /* fall back to legacy interrupt*/
+       ret = request_irq(pdev->irq, &usb_hcd_irq, IRQF_SHARED,
+                       hcd->irq_descr, hcd);
+       if (ret) {
+               xhci_err(xhci, "request interrupt %d failed\n",
+                               pdev->irq);
+               return ret;
+       }
+       hcd->irq = pdev->irq;
+       return 0;
+}
+
 /*
  * Start the HC after it was halted.
  *
@@ -413,9 +452,8 @@ int xhci_run(struct usb_hcd *hcd)
 {
        u32 temp;
        u64 temp_64;
-       u32 ret;
+       int ret;
        struct xhci_hcd *xhci = hcd_to_xhci(hcd);
-       struct pci_dev  *pdev = to_pci_dev(xhci_to_hcd(xhci)->self.controller);
 
        /* Start the xHCI host controller running only after the USB 2.0 roothub
         * is setup.
@@ -426,34 +464,10 @@ int xhci_run(struct usb_hcd *hcd)
                return xhci_run_finished(xhci);
 
        xhci_dbg(xhci, "xhci_run\n");
-       /* unregister the legacy interrupt */
-       if (hcd->irq)
-               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);
+       ret = xhci_try_enable_msi(hcd);
        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);
-               if (ret) {
-                       xhci_err(xhci, "request interrupt %d failed\n",
-                                       pdev->irq);
-                       return ret;
-               }
-               hcd->irq = pdev->irq;
-       }
+               return ret;
 
 #ifdef CONFIG_USB_XHCI_HCD_DEBUGGING
        init_timer(&xhci->event_ring_timer);