From: Tomasz Figa <tfiga@google.com>
To: Kieran Bingham <kieran.bingham@ideasonboard.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
Linux Media Mailing List <linux-media@vger.kernel.org>,
g.liakhovetski@gmx.de, olivier.braun@stereolabs.com,
troy.kisky@boundarydevices.com,
Randy Dunlap <rdunlap@infradead.org>,
philipp.zabel@gmail.com,
Mauro Carvalho Chehab <mchehab@kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v4 6/6] media: uvcvideo: Move decode processing to process context
Date: Tue, 7 Aug 2018 18:54:02 +0900 [thread overview]
Message-ID: <CAAFQd5CQEhmuLbs0dmGfu66x1Xq1V_kOT0bV_DoPitkkOX5Q4A@mail.gmail.com> (raw)
In-Reply-To: <cae511f90085701e7093ce39dc8dabf8fc16b844.1522168131.git-series.kieran.bingham@ideasonboard.com>
Hi Kieran,
On Wed, Mar 28, 2018 at 1:47 AM Kieran Bingham
<kieran.bingham@ideasonboard.com> wrote:
[snip]
> @@ -1544,25 +1594,29 @@ static int uvc_alloc_urb_buffers(struct uvc_streaming *stream,
> */
> static void uvc_uninit_video(struct uvc_streaming *stream, int free_buffers)
> {
> - struct urb *urb;
> - unsigned int i;
> + struct uvc_urb *uvc_urb;
>
> uvc_video_stats_stop(stream);
>
> - for (i = 0; i < UVC_URBS; ++i) {
> - struct uvc_urb *uvc_urb = &stream->uvc_urb[i];
> + /*
> + * We must poison the URBs rather than kill them to ensure that even
> + * after the completion handler returns, any asynchronous workqueues
> + * will be prevented from resubmitting the URBs
> + */
> + for_each_uvc_urb(uvc_urb, stream)
> + usb_poison_urb(uvc_urb->urb);
>
> - urb = uvc_urb->urb;
> - if (urb == NULL)
> - continue;
> + flush_workqueue(stream->async_wq);
>
> - usb_kill_urb(urb);
> - usb_free_urb(urb);
> + for_each_uvc_urb(uvc_urb, stream) {
> + usb_free_urb(uvc_urb->urb);
> uvc_urb->urb = NULL;
> }
>
> if (free_buffers)
> uvc_free_urb_buffers(stream);
> +
> + destroy_workqueue(stream->async_wq);
In our testing, this function ends up being called twice, if before
suspend the camera is streaming and if the camera disconnects between
suspend and resume. This is because uvc_video_suspend() calls this
function (with free_buffers = 0), but uvc_video_resume() wouldn't call
uvc_init_video() due to an earlier failure and uvc_v4l2_release()
would end up calling this function again, while the workqueue is
already destroyed.
The following diff seems to take care of it:
8<~~~
diff --git a/drivers/media/usb/uvc/uvc_video.c
b/drivers/media/usb/uvc/uvc_video.c
index c5e0ab564b1a..6fb890c8ba67 100644
--- a/drivers/media/usb/uvc/uvc_video.c
+++ b/drivers/media/usb/uvc/uvc_video.c
@@ -1493,10 +1493,11 @@ static void uvc_uninit_video(struct
uvc_streaming *stream, int free_buffers)
uvc_urb->urb = NULL;
}
- if (free_buffers)
+ if (free_buffers) {
uvc_free_urb_buffers(stream);
-
- destroy_workqueue(stream->async_wq);
+ destroy_workqueue(stream->async_wq);
+ stream->async_wq = NULL;
+ }
}
/*
@@ -1648,10 +1649,12 @@ static int uvc_init_video(struct uvc_streaming
*stream, gfp_t gfp_flags)
uvc_video_stats_start(stream);
- stream->async_wq = alloc_workqueue("uvcvideo", WQ_UNBOUND | WQ_HIGHPRI,
- 0);
- if (!stream->async_wq)
- return -ENOMEM;
+ if (!stream->async_wq) {
+ stream->async_wq = alloc_workqueue("uvcvideo",
+ WQ_UNBOUND | WQ_HIGHPRI, 0);
+ if (!stream->async_wq)
+ return -ENOMEM;
+ }
if (intf->num_altsetting > 1) {
struct usb_host_endpoint *best_ep = NULL;
~~~>8
Best regards,
Tomasz
next prev parent reply other threads:[~2018-08-07 9:54 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <cover.3cb9065dabdf5d455da508fb4109201e626d5ee7.1522168131.git-series.kieran.bingham@ideasonboard.com>
2018-03-27 16:45 ` [PATCH v4 1/6] media: uvcvideo: Refactor URB descriptors Kieran Bingham
2018-03-27 16:45 ` [PATCH v4 2/6] media: uvcvideo: Convert decode functions to use new context structure Kieran Bingham
2018-03-27 16:46 ` [PATCH v4 3/6] media: uvcvideo: Protect queue internals with helper Kieran Bingham
2018-03-27 16:46 ` [PATCH v4 4/6] media: uvcvideo: queue: Simplify spin-lock usage Kieran Bingham
2018-07-30 19:57 ` Laurent Pinchart
2018-11-06 15:10 ` Kieran Bingham
2018-03-27 16:46 ` [PATCH v4 5/6] media: uvcvideo: queue: Support asynchronous buffer handling Kieran Bingham
2018-03-27 16:46 ` [PATCH v4 6/6] media: uvcvideo: Move decode processing to process context Kieran Bingham
2018-06-04 12:09 ` Guennadi Liakhovetski
2018-06-04 12:34 ` Kieran Bingham
2018-07-30 22:11 ` Laurent Pinchart
2018-08-07 9:54 ` Tomasz Figa [this message]
2018-08-07 23:06 ` Laurent Pinchart
2018-08-07 23:13 ` Laurent Pinchart
2018-08-08 3:50 ` Tomasz Figa
2018-08-08 13:49 ` Kieran Bingham
2018-11-06 15:13 ` Kieran Bingham
2018-11-07 4:38 ` Tomasz Figa
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