Re: [PATCH v2 5/5] xhci: Correct handling of one-TRB isoc TD on Etron xHCI host

[Mathias Nyman <mathias.nyman@linux.intel.com>]

On 28.10.2024 4.53, Kuangyi Chiang wrote:
> Unplugging a USB3.0 webcam while streaming results in errors
> like this:
> 
> [ 132.646387] xhci_hcd 0000:03:00.0: ERROR Transfer event TRB DMA ptr not part of current TD ep_index 18 comp_code 13
> [ 132.646446] xhci_hcd 0000:03:00.0: Looking for event-dma 000000002fdf8630 trb-start 000000002fdf8640 trb-end 000000002fdf8650 seg-start 000000002fdf8000 seg-end 000000002fdf8ff0
> [ 132.646560] xhci_hcd 0000:03:00.0: ERROR Transfer event TRB DMA ptr not part of current TD ep_index 18 comp_code 13
> [ 132.646568] xhci_hcd 0000:03:00.0: Looking for event-dma 000000002fdf8660 trb-start 000000002fdf8670 trb-end 000000002fdf8670 seg-start 000000002fdf8000 seg-end 000000002fdf8ff0
> 
> If an error is detected while processing an one-TRB isoc TD,
> the Etron xHC generates two transfer events for the TRB that
> the error was detected on. The first event is "USB Transcation
> Error", and the second event is "Success".
> 
> The xHCI driver will handle the TD after the first event and
> remove it from its internal list, and then print an "Transfer
> event TRB DMA ptr not part of current TD" error message after
> the second event.
> 
> As a solution, we can set the flag after the first error event
> and don't print the error message after the second event if
> the flag is set.
> 
> Commit ad808333d820 ("Intel xhci: Ignore spurious successful
> event.") implements a similar mechanism that we can reuse to
> solve this problem since short transfer and transfer error
> doesn't occur concurrently. Also, rename the flag to make it
> more meaningful.
> 
> Check if the XHCI_ETRON_HOST quirk flag is set before invoking
> the workaround in process_isoc_td().
> 
> This patch doesn't affect other host controllers that have the
> XHCI_SPURIOUS_SUCCESS quirk flag applied.
> 
> Signed-off-by: Kuangyi Chiang <ki.chiang65@gmail.com>

I'm leaving this out of the series due to both ongoing discussion about
this patch, and because it conflicts with another series touching
handle_tx_event()

All other patches in series are added

Thanks
Mathias