RE: [PATCH] usb: gadget: uvc_video: unlock before submitting a request to ep

[Pandey, Radhey Shyam]

> -----Original Message-----
> From: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx>
> Sent: Friday, January 19, 2024 7:45 AM
> To: Pandey, Radhey Shyam <radhey.shyam.pandey@xxxxxxx>
> Cc: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx>; Dan Scally
> <dan.scally@xxxxxxxxxxxxxxxx>; Kuen-Han Tsai <khtsai@xxxxxxxxxx>;
> gregkh@xxxxxxxxxxxxxxxxxxx; laurent.pinchart@xxxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; linux-usb@xxxxxxxxxxxxxxx; Simek, Michal
> <michal.simek@xxxxxxx>; Mehta, Piyush <piyush.mehta@xxxxxxx>;
> Paladugu, Siva Durga Prasad <siva.durga.prasad.paladugu@xxxxxxx>
> Subject: Re: [PATCH] usb: gadget: uvc_video: unlock before submitting a
> request to ep
> 
> Hi,
> 
> On Wed, Jan 10, 2024, Pandey, Radhey Shyam wrote:
> >
> > Thanks, Thinh. I came across this thread and wanted to check if you
> > have some fix ready?

I have added Mubin to this thread as he is working on validating below fix.

> 
> Would you mind test this change to see if it fixes the issue:
> 
> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index
> 8d1881adcd80..f40c7b9105cc 100644
> --- a/drivers/usb/dwc3/gadget.c
> +++ b/drivers/usb/dwc3/gadget.c
> @@ -1808,6 +1808,7 @@ static int dwc3_prepare_trbs(struct dwc3_ep *dep)
>  	return ret;
>  }
> 
> +static void dwc3_gadget_ep_skip_trbs(struct dwc3_ep *dep, struct
> +dwc3_request *req);
>  static void dwc3_gadget_ep_cleanup_cancelled_requests(struct dwc3_ep
> *dep);  static void dwc3_gadget_restore_requests(struct dwc3_ep *dep);
> 
> @@ -1874,9 +1875,27 @@ static int __dwc3_gadget_kick_transfer(struct
> dwc3_ep *dep)
>  		list_for_each_entry_safe(req, tmp, &dep->started_list, list)
>  			dwc3_gadget_move_cancelled_request(req,
> DWC3_REQUEST_STATUS_DEQUEUED);
> 
> -		/* If ep isn't started, then there's no end transfer pending */
> -		if (!(dep->flags & DWC3_EP_END_TRANSFER_PENDING))
> -			dwc3_gadget_ep_cleanup_cancelled_requests(dep);
> +		if ((dep->flags & DWC3_EP_DELAY_START) ||
> +		    (dep->flags & DWC3_EP_WAIT_TRANSFER_COMPLETE) ||
> +		    (dep->flags & DWC3_EP_TRANSFER_STARTED)) {
> +			/* If ep isn't started, then there's no end transfer
> pending */
> +			if (!(dep->flags &
> DWC3_EP_END_TRANSFER_PENDING))
> +
> 	dwc3_gadget_ep_cleanup_cancelled_requests(dep);
> +		} else {
> +			/*
> +			 * To be in this condition means usb_ep_queue() isn't
> +			 * completed yet. Since the controller hasn't owned
> the
> +			 * requests yet, don't give back the requests on failed
> +			 * usb_ep_queue. Simply remove them from the
> endpoint's
> +			 * list.
> +			 */
> +			while (!list_empty(&dep->cancelled_list)) {
> +				req = next_request(&dep->cancelled_list);
> +				dwc3_gadget_ep_skip_trbs(dep, req);
> +				dwc3_gadget_del_and_unmap_request(dep,
> req, -EINPROGRESS);
> +				req->status =
> DWC3_REQUEST_STATUS_COMPLETED;
> +			}
> +		}
> 
>  		return ret;
>  	}
> 
> BTW, what was the error code returned from usb_ep_queue()? Is it -
> ETIMEDOUT?
> 
> Thanks,
> Thinh