RE: [PATCH] usb: dwc3: gadget: issue a stop command for ISOC endpoint

[Zengtao (B)]

Hi balbi:

I got this issue in the UVC application, and I think this issue still exist in the 
latest dwc3 driver.

And we should issue an stop command and the queue is empty when it's 
ISOC transfer, otherwise we will end up with MISS ISOC error for all the 
upcoming transfers.

So I think you can test the UVC application with the latest driver.

Regards
Zengtao 

>-----Original Message-----
>From: Felipe Balbi [mailto:felipe.balbi@xxxxxxxxxxxxxxx]
>Sent: Monday, January 21, 2019 4:56 PM
>To: Zengtao (B) <prime.zeng@xxxxxxxxxxxxx>
>Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>;
>linux-usb@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Laurent
>Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
>Subject: RE: [PATCH] usb: dwc3: gadget: issue a stop command for ISOC
>endpoint
>
>* PGP Signed by an unknown key
>
>
>Hi,
>
>"Zengtao (B)" <prime.zeng@xxxxxxxxxxxxx> writes:
>>>-----Original Message-----
>>>From: Felipe Balbi [mailto:felipe.balbi@xxxxxxxxxxxxxxx]
>>>Sent: Monday, January 21, 2019 4:17 PM
>>>To: Zengtao (B) <prime.zeng@xxxxxxxxxxxxx>
>>>Cc: Zengtao (B) <prime.zeng@xxxxxxxxxxxxx>; Greg Kroah-Hartman
>>><gregkh@xxxxxxxxxxxxxxxxxxx>; linux-usb@xxxxxxxxxxxxxxx;
>>>linux-kernel@xxxxxxxxxxxxxxx
>>>Subject: Re: [PATCH] usb: dwc3: gadget: issue a stop command for
>ISOC
>>>endpoint
>>>
>>>> Old Signed by an unknown key
>>>
>>>
>>>Hi,
>>>
>>>Zeng Tao <prime.zeng@xxxxxxxxxxxxx> writes:
>>>> For ISOC transfers, if there is no available data for a period, we
>>>> need to stop the transfer by issue a stop command, otherwise, all
>>>> the upcoming transfers will started by update transfer command,
>and
>>>> will be dropped with MISS ISOC errors.
>>>
>>>We, actually, have code to handle missed isoc errors now. Have you
>>>tested with that applied? Which kernel are you using? Can you share
>>>tracepoints captured with v5.0-rc3?
>>>
>>
>> Not v5.0-rc3, but I tested it based on 4.9 with backported dwc3
>> driver. And with UVC application, it's very easy to reproduce it.
>
>Ok, so it could be that you missed patches while backporting, right?
>How can I reproduce this? What do I need? Care to give detailed
>instructions?
>
>--
>balbi
>
>* Unknown Key
>* 0xE11A9906