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Subject: Re: [PATCH] usb: dwc3: gadget: Avoid canceling current request for
 queuing error
To:     Felipe Balbi <balbi@kernel.org>, gregkh@linuxfoundation.org
Cc:     linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
        jackp@codeaurora.org
References: <1618439388-20427-1-git-send-email-wcheng@codeaurora.org>
 <87mtu0njvj.fsf@kernel.org>
From:   Wesley Cheng <wcheng@codeaurora.org>
Message-ID: <677afbd3-6c72-29c0-ca25-88dd1bff335a@codeaurora.org>
Date:   Thu, 15 Apr 2021 10:51:01 -0700
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On 4/14/2021 11:26 PM, Felipe Balbi wrote:
> Wesley Cheng <wcheng@codeaurora.org> 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@codeaurora.org>
>> ---
>>  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.

Thanks
Wesley Cheng

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