Re: [PATCH] media: v4l2-fh: define v4l2_fh struct regardless of condition

From: Hans Verkuil
Date: Wed Mar 25 2020 - 12:54:35 EST


On 3/23/20 3:30 AM, Seungchul Kim wrote:
> v4l2_fh struct define differently by CONFIG_V4L2_MEM2MEM_DEV.
> If some vendors use CONFIG_V4L2_MEM2MEM_DEV by module, it can make the
> mismatch of v4l2_fh sturct.
>
> By the mismatch, the following error occurs.
> ===============================
> [ 7.533506] v4l2_mem2mem: disagrees about version of symbol video_devdata
> [ 7.533594] v4l2_mem2mem: Unknown symbol video_devdata (err -22)
> [ 7.535319] v4l2_mem2mem: disagrees about version of symbol
> v4l2_event_pending
> [ 7.542532] v4l2_mem2mem: Unknown symbol v4l2_event_pending (err -22)
> ===============================
>
> So v4l2_fh struct is modified to does not have dependency for
> CONFIG_V4L2_MEM2MEM_DEV.
>
> Signed-off-by: Seungchul Kim <sc377.kim@xxxxxxxxxxx>
> ---
> include/media/v4l2-fh.h | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/include/media/v4l2-fh.h b/include/media/v4l2-fh.h index
> 53b4dbb..b5b3e00 100644
> --- a/include/media/v4l2-fh.h
> +++ b/include/media/v4l2-fh.h
> @@ -53,9 +53,7 @@ struct v4l2_fh {
> unsigned int navailable;
> u32 sequence;
>
> -#if IS_ENABLED(CONFIG_V4L2_MEM2MEM_DEV)
> struct v4l2_m2m_ctx *m2m_ctx;
> -#endif

This is a good change, but please also remove the same #if from v4l2_ioctl_get_lock()
in drivers/media/v4l2-core/v4l2-ioctl.c. That is now no longer needed there either
and without removing that those vendor drivers would be using the wrong lock.

Regards,

Hans

> };
>
> /**
> --
> 2.7.4
>