On Mon, 24 Feb 2014, Mathias Nyman wrote: > 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.ny...@linux.intel.com> > --- > drivers/usb/host/xhci-pci.c | 11 ++++++++++- > 1 file changed, 10 insertions(+), 1 deletion(-) > > diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c > index 04f986d..ea7158b 100644 > --- a/drivers/usb/host/xhci-pci.c > +++ b/drivers/usb/host/xhci-pci.c > @@ -190,6 +190,10 @@ 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 USB-2 roothub runtime suspend until USB-3 is initialized. */ > + pm_runtime_get_noresume(&dev->dev);
Strictly speaking, this prevents the _controller_ from going into runtime suspend -- not the root hub. > + > /* 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 > @@ -199,7 +203,7 @@ 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); > @@ -228,12 +232,17 @@ 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; > } Apart from nit about the comment, Acked-by: Alan Stern <st...@rowland.harvard.edu> -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
