Re: [PATCH v3 2/3] media: uvcvideo: Do not halt the device after disconnect

From: Ricardo Ribalda
Date: Wed Nov 22 2023 - 05:26:37 EST


Hi Sergey

On Wed, 22 Nov 2023 at 09:01, Sergey Senozhatsky
<senozhatsky@xxxxxxxxxxxx> wrote:
>
> On (23/11/22 16:47), Sergey Senozhatsky wrote:
> > Can the following happen?
>
> Consider the following case (when CPU1 experienced a delay, a preemption
> or anything):
>
> > CPU0 CPU1
> > uvc_disconnect()
> > uvc_video_stop_streaming()
> > usb_set_intfdata()
> > uvc_unregister_video()
> >
> > if (!smp_load(&dev->disconnected))
> >
> > smp_store_release(&dev->disconnected, true);
> >
> > kref_put(&dev->ref, uvc_delete);
>
> > uvc_video_halt()
>
> That uvc_video_halt() cannot be legal, right?

This patch only takes care of calls to uvc_video_stop_streaming()
after .disconnect.

Guenter's patch from this series should take care of the concurrent
calls. I will resend making it explicit.

Thanks!


--
Ricardo Ribalda