Re: [PATCH 1/1] usb: xhci: apply XHCI_AVOID_BEI quirk to Intel ValleyView and LynxPoint LP

[Lu, Baolu]

On 03/12/2015 03:54 PM, Greg Kroah-Hartman wrote:
> On Thu, Mar 12, 2015 at 09:39:06AM +0800, Lu Baolu wrote:
> > When a device with an isochronous endpoint is plugged into the Intel
> > xHCI host controller, and the driver submits multiple frames per URB,
> > the xHCI driver will set the Block Event Interrupt (BEI) flag on all
> > but the last TD for the URB. This causes the host controller to place
> > an event on the event ring, but not send an interrupt. When the last
> > TD for the URB completes, BEI is cleared, and we get an interrupt for
> > the whole URB.
> >
> > However,  under some Intel xHCI host controllers like ValleyView and
> > Lynx Point LP, if the event ring is full of events from transfers with
> > BEI set, a "Event Ring is Full" event will be posted to the last entry
> > of the event ring, but no interrupt is generated. Host will cease all
> > transfer and command executions  and  wait until software completes
> > handling the pending events in event ring. That means xHC stops but
> > event of "event ring is full" is not notified. As the result, the xHC
> > looks like dead to user.
> >
> > The patch is to apply XHCI_AVOID_BEI to Intel VallyView and Lynx Point
> > LP devices. And it should be backported to kernels as old as 3.0, that
> > contains the commit 69e848c2090a ("Intel xhci: Support EHCI/xHCI port
> > switching.")
> >
> > Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
> > Cc: stable@xxxxxxxxxxxxxxx
> > ---
> >   drivers/usb/host/xhci-pci.c | 5 +++++
> >   1 file changed, 5 insertions(+)
> >
> > diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
> > index fd53c9e..5aa4893 100644
> > --- a/drivers/usb/host/xhci-pci.c
> > +++ b/drivers/usb/host/xhci-pci.c
> > @@ -40,6 +40,7 @@
> >   #define PCI_DEVICE_ID_INTEL_CHERRYVIEW_XHCI		0x22b5
> >   #define PCI_DEVICE_ID_INTEL_SUNRISEPOINT_H_XHCI		0xa12f
> >   #define PCI_DEVICE_ID_INTEL_SUNRISEPOINT_LP_XHCI	0x9d2f
> > +#define	PCI_DEVICE_ID_INTEL_VALLEYVIEW_XHCI		0x0f35
> Minor nit, you added a tab where the rest of the file was using a space
> :(

Yes, thanks for reminding.

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