On Thu, Mar 12, 2015 at 8:14 PM, Alistair Grant <akgrant0...@gmail.com> wrote:
> On Thu, Mar 12, 2015 at 11:15 AM, Lu Baolu <baolu...@linux.intel.com> 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 Intel xHCI host controllers, if the event ring is full
>> of events from transfers with BEI set, an "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 the 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.
>>
>> This patch is to apply XHCI_AVOID_BEI quirk to Intel xHC 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...@linux.intel.com>
>> Cc: sta...@vger.kernel.org
>> ---
>> drivers/usb/host/xhci-pci.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
>> index fd53c9e..2af32e2 100644
>> --- a/drivers/usb/host/xhci-pci.c
>> +++ b/drivers/usb/host/xhci-pci.c
>> @@ -115,6 +115,7 @@ static void xhci_pci_quirks(struct device *dev, struct
>> xhci_hcd *xhci)
>> if (pdev->vendor == PCI_VENDOR_ID_INTEL) {
>> xhci->quirks |= XHCI_LPM_SUPPORT;
>> xhci->quirks |= XHCI_INTEL_HOST;
>> + xhci->quirks |= XHCI_AVOID_BEI;
>> }
>> if (pdev->vendor == PCI_VENDOR_ID_INTEL &&
>> pdev->device ==
>> PCI_DEVICE_ID_INTEL_PANTHERPOINT_XHCI) {
>> @@ -130,7 +131,6 @@ static void xhci_pci_quirks(struct device *dev, struct
>> xhci_hcd *xhci)
>> * PPT chipsets.
>> */
>> xhci->quirks |= XHCI_SPURIOUS_REBOOT;
>> - xhci->quirks |= XHCI_AVOID_BEI;
>> }
>> if (pdev->vendor == PCI_VENDOR_ID_INTEL &&
>> pdev->device == PCI_DEVICE_ID_INTEL_LYNXPOINT_LP_XHCI) {
>> --
>> 2.1.0
>>
>> --
>
> This works for me...
>
> Computer: Dell XPS13 9333
> USB controller: Intel Corporation 8 Series USB xHCI HC (rev 04)
> (prog-if 30 [XHCI])
> Kernel: 3.19.1
> USB Device: Hauppauge USB-Live2
>
> Please let me know if I can help in any other way.
>
> Tested-by: Alistair Grant <akgrant0...@gmail.com>
Just FYI...
I was able to test this on a slightly older laptop that had both USB2
and USB3 ports and can confirm that it also works there:
00:14.0 USB controller: Intel Corporation 7 Series/C210 Series Chipset
Family USB xHCI Host Controller (rev 04)
Thanks,
Alistair
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