Re: [PATCH] usb: dwc3: gadget: giveback request if start transfer fail

From: Felipe Balbi
Date: Wed Apr 30 2014 - 15:58:42 EST


Hi,

On Thu, May 01, 2014 at 02:36:08AM -0400, Zhuang Jin Can wrote:
> At least we should giveback the current request to the
> gadget. Otherwise, the gadget will be stuck without knowing
> anything.
>
> It was oberved that the failure can happen if the request is
> queued when the run/stop bit of controller is not set.

why is your gadget queueing any requests before calling ->udc_start() ?

A better question, what modification have you done to udc-core.c which
broke this ? udc-core *always* calls ->udc_start() by the time you load
a gadget driver so this case will *never* happen. Whatever modification
you did, broke this assumption and I will *not* accept this patch
because the bug is elsewhere and *not* in mainline kernel.

> Signed-off-by: Zhuang Jin Can <jin.can.zhuang@xxxxxxxxx>
> ---
> drivers/usb/dwc3/gadget.c | 4 +---
> 1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
> index 70715ee..8d0c3c7 100644
> --- a/drivers/usb/dwc3/gadget.c
> +++ b/drivers/usb/dwc3/gadget.c
> @@ -1000,9 +1000,7 @@ static int __dwc3_gadget_kick_transfer(struct dwc3_ep *dep, u16 cmd_param,
> * here and stop, unmap, free and del each of the linked
> * requests instead of what we do now.
> */
> - usb_gadget_unmap_request(&dwc->gadget, &req->request,
> - req->direction);
> - list_del(&req->list);
> + dwc3_gadget_giveback(dep, req, -ESHUTDOWN);
> return ret;
> }
>
> --
> 1.7.9.5
>

--
balbi

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