Re: [RESEND PATCH v3 2/2] usb: dwc3: Wait for control tranfer completed when stopping gadget

From: Baolin Wang
Date: Thu Oct 13 2016 - 04:01:57 EST


On 13 October 2016 at 15:54, Felipe Balbi <balbi@xxxxxxxxxx> wrote:
>
> Hi,
>
> Baolin Wang <baolin.wang@xxxxxxxxxx> writes:
>> Hi,
>>
>> On 13 October 2016 at 15:08, Felipe Balbi <balbi@xxxxxxxxxx> wrote:
>>>
>>> Hi,
>>>
>>> Baolin Wang <baolin.wang@xxxxxxxxxx> writes:
>>>> @@ -1487,10 +1496,22 @@ static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on)
>>>>
>>>> is_on = !!is_on;
>>>>
>>>> +try_again:
>>>> spin_lock_irqsave(&dwc->lock, flags);
>>>> ret = dwc3_gadget_run_stop(dwc, is_on, false);
>>>> spin_unlock_irqrestore(&dwc->lock, flags);
>>>>
>>>> + if (ret == -EBUSY) {
>>>> + ret = wait_for_completion_timeout(&dwc->ep0_in_setup,
>>>> + msecs_to_jiffies(500));
>>>> + if (ret == 0) {
>>>> + dev_err(dwc->dev, "timeout to stop gadget.\n");
>>>> + ret = -ETIMEDOUT;
>>>> + } else {
>>>> + goto try_again;
>>>
>>> you are not really reading my comments. It's the third time I tell you
>>> there's no need for try_again. If you can't complete a control transfer
>>> in 500ms, you already have other issues. Take this thing out of here.
>>
>> I think you misunderstood the code. If there is 500ms timeout, we will
>> return '-ETIMEDOUT' error. If the control transfer is completed before
>> timeout, we can not just return and we need try again to stop the
>> gadget, right? Any other good suggestion? Thanks.
>
> Yeah, change the patch a bit so you wait for completion before calling
> dwc3_gadget_runt_stop()? I mean, move the !is_on && ep0_state check
> before calling dwc3_gadget_run_stop() and wait_for_completion_timeout()
> there.

OK. I will refactor the patch. Thanks.

>
> --
> balbi



--
Baolin.wang
Best Regards