Re: [PATCH] usb: dwc3: gadget: Avoid canceling current request for queuing error

From: Thinh Nguyen
Date: Thu Apr 15 2021 - 15:29:17 EST


Thinh Nguyen wrote:
> Wesley Cheng wrote:
>>
>>
>> On 4/14/2021 11:26 PM, Felipe Balbi wrote:
>>> Wesley Cheng <wcheng@xxxxxxxxxxxxxx> writes:
>>>
>>>> If an error is received when issuing a start or update transfer
>>>> command, the error handler will stop all active requests (including
>>>> the current USB request), and call dwc3_gadget_giveback() to notify
>>>> function drivers of the requests which have been stopped. Avoid
>>>> having to cancel the current request which is trying to be queued, as
>>>> the function driver will handle the EP queue error accordingly.
>>>> Simply unmap the request as it was done before, and allow previously
>>>> started transfers to be cleaned up.
>>>>
>>>> Signed-off-by: Wesley Cheng <wcheng@xxxxxxxxxxxxxx>
>>>> ---
>>>> drivers/usb/dwc3/gadget.c | 5 +++++
>>>> 1 file changed, 5 insertions(+)
>>>>
>>>> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
>>>> index e1b04c97..4200775 100644
>>>> --- a/drivers/usb/dwc3/gadget.c
>>>> +++ b/drivers/usb/dwc3/gadget.c
>>>> @@ -1399,6 +1399,11 @@ static int __dwc3_gadget_kick_transfer(struct dwc3_ep *dep)
>>>> if (ret == -EAGAIN)
>>>> return ret;
>>>>
>>>> + /* Avoid canceling current request, as it has not been started */
>>>> + if (req->trb)
>>>> + memset(req->trb, 0, sizeof(struct dwc3_trb));
>>>
>>> we don't need a full memset. I think ensuring HWO bit is zero is enough.
>>>
>> Hi Felipe,
>>
>> Thanks for the input/review, will make this change to just clear the HWO.
>>
>
> Make sure to increment the dequeue pointer also. I think you can use
> dwc3_gadget_ep_skip_trbs().
>

Nevermind. There maybe a problem with using dwc3_gadget_ep_skip_trbs().

Thinh