Re: [PATCH v2 1/1] usb: xhci: apply XHCI_AVOID_BEI quirk to all Intel xHCI controllers

From: Mathias Nyman
Date: Mon Mar 16 2015 - 08:54:15 EST


On 15.03.2015 21:18, Alistair Grant wrote:
> On Sun, Mar 15, 2015 at 3:54 PM, Alistair Grant <akgrant0710@xxxxxxxxx> wrote:
>> On Thu, Mar 12, 2015 at 8:14 PM, Alistair Grant <akgrant0710@xxxxxxxxx> wrote:
>>> On Thu, Mar 12, 2015 at 11:15 AM, Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx> 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.lu@xxxxxxxxxxxxxxx>
>>>> Cc: stable@xxxxxxxxxxxxxxx
>>>> ---
>>>> 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 <akgrant0710@xxxxxxxxx>
>>
>> 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)
>
> It looks like I may have signed-off a little too soon. While the patch is
> working correctly if the Hauppauge Live2 is plugged in after the system has
> booted and settled down (my normal use case), it fails if the Live2 is
> plugged in while the system is booted up.
>
> Unplugging the Live2 after recording (which appears to succeed from the
> command line, but had no audio), executing lsusb just hangs.
>
> I've included what I think is the relevant portions of /var/log/syslog
> below. If you'd like the entire log file posted somewhere please let me
> know.

Hi

What kernel did you try this patch on?

The output look a bit like the regression in 4.0-rc3 caused by:
commit 27082e2654dc148078b0abdfc3c8e5ccbde0ebfa
xhci: Clear the host side toggle manually when endpoint is 'soft reset'

which will be reverted (in 4.0-rc5 I hope).

If you boot the same base kernel without the patch does it work then?

-Mathias

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