On 4/15/2021 12:28 PM, Thinh Nguyen wrote: > 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 > Hi Thinh, Thank you for your input. In this case (if kick transfer fails w/ an error), would we still need to mess with the enqueue/dequeue pointers? Not sure if my assumption is correct, but the TRB wouldn't have been started, so we can use the same (failed) TRB for future requests, right? I think one thing I will need to update is to loop through num_trbs and clear all HWO bits if the above is not needed. Thanks Wesley Cheng -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project
