On 2/14/19 10:18 AM, Paul Kocialkowski wrote: > Hi, > > On Thu, 2019-02-14 at 09:59 +0100, Hans Verkuil wrote: >> On 2/14/19 9:37 AM, Paul Kocialkowski wrote: >>> Check that our queues are not busy before setting the format or return >>> EBUSY if that's the case. This ensures that our format can't change >>> once buffers are allocated for the queue. >>> >>> Signed-off-by: Paul Kocialkowski <paul.kocialkow...@bootlin.com> >>> --- >>> drivers/staging/media/sunxi/cedrus/cedrus_video.c | 14 ++++++++++++++ >>> 1 file changed, 14 insertions(+) >>> >>> diff --git a/drivers/staging/media/sunxi/cedrus/cedrus_video.c >>> b/drivers/staging/media/sunxi/cedrus/cedrus_video.c >>> index b5cc79389d67..3420a938a613 100644 >>> --- a/drivers/staging/media/sunxi/cedrus/cedrus_video.c >>> +++ b/drivers/staging/media/sunxi/cedrus/cedrus_video.c >>> @@ -282,8 +282,15 @@ static int cedrus_s_fmt_vid_cap(struct file *file, >>> void *priv, >>> { >>> struct cedrus_ctx *ctx = cedrus_file2ctx(file); >>> struct cedrus_dev *dev = ctx->dev; >>> + struct vb2_queue *vq; >>> int ret; >>> >>> + vq = v4l2_m2m_get_vq(ctx->fh.m2m_ctx, f->type); >>> + if (!vq) >>> + return -EINVAL; >> >> Can this ever happen? > > I guess not, or something would be very wrong. > I have seen this check around when looking at how other drivers > implement this, but it does seem overkill. > > Should I get rid of it in v2?
Yes please! Regards, Hans > > Cheers, > > Paul > >> Regards, >> >> Hans >> >>> + else if (vb2_is_busy(vq)) >>> + return -EBUSY; >>> + >>> ret = cedrus_try_fmt_vid_cap(file, priv, f); >>> if (ret) >>> return ret; >>> @@ -299,8 +306,15 @@ static int cedrus_s_fmt_vid_out(struct file *file, >>> void *priv, >>> struct v4l2_format *f) >>> { >>> struct cedrus_ctx *ctx = cedrus_file2ctx(file); >>> + struct vb2_queue *vq; >>> int ret; >>> >>> + vq = v4l2_m2m_get_vq(ctx->fh.m2m_ctx, f->type); >>> + if (!vq) >>> + return -EINVAL; >>> + else if (vb2_is_busy(vq)) >>> + return -EBUSY; >>> + >>> ret = cedrus_try_fmt_vid_out(file, priv, f); >>> if (ret) >>> return ret; >>>