xhci: Prevent runtime pm from autosuspending during initialization

commit bcffae7708eb8352f44dc510b326541fe43a02a4 upstream.

xHCI driver has its own pci probe function that will call usb_hcd_pci_probe
to register its usb-2 bus, and then continue to manually register the
usb-3 bus. usb_hcd_pci_probe does a pm_runtime_put_noidle at the end and
might thus trigger a runtime suspend before the usb-3 bus is ready.

Prevent the runtime suspend by increasing the usage count in the
beginning of xhci_pci_probe, and decrease it once the usb-3 bus is
ready.

xhci-platform driver is not using usb_hcd_pci_probe to set up
busses and should not need to have it's usage count increased during probe.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
index 3581416a24d8658bf672016e7df9d6b0ab0e418a..3c9992a5ab7be1447900e4e19da7c0bd54143b33 100644 (file)
--- a/drivers/usb/host/xhci-pci.c
+++ b/drivers/usb/host/xhci-pci.c
@@ -161,6 +161,10 @@ static int xhci_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
        struct usb_hcd *hcd;
 
        driver = (struct hc_driver *)id->driver_data;
+
+       /* Prevent runtime suspending between USB-2 and USB-3 initialization */
+       pm_runtime_get_noresume(&dev->dev);
+
        /* Register the USB 2.0 roothub.
         * FIXME: USB core must know to register the USB 2.0 roothub first.
         * This is sort of silly, because we could just set the HCD driver flags
@@ -170,7 +174,7 @@ static int xhci_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
        retval = usb_hcd_pci_probe(dev, id);
 
        if (retval)
-               return retval;
+               goto put_runtime_pm;
 
        /* USB 2.0 roothub is stored in the PCI device now. */
        hcd = dev_get_drvdata(&dev->dev);
@@ -199,12 +203,17 @@ static int xhci_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
        if (xhci->quirks & XHCI_LPM_SUPPORT)
                hcd_to_bus(xhci->shared_hcd)->root_hub->lpm_capable = 1;
 
+       /* USB-2 and USB-3 roothubs initialized, allow runtime pm suspend */
+       pm_runtime_put_noidle(&dev->dev);
+
        return 0;
 
 put_usb3_hcd:
        usb_put_hcd(xhci->shared_hcd);
 dealloc_usb2_hcd:
        usb_hcd_pci_remove(dev);
+put_runtime_pm:
+       pm_runtime_put_noidle(&dev->dev);
        return retval;
 }