Re: [PATCH v10.1] media: Add registration helpers for V4L2 flash sub-devices

[Hans Verkuil <hverkuil@xs4all.nl>]

On 06/19/2015 09:31 AM, Jacek Anaszewski wrote:
> This patch adds helper functions for registering/unregistering
> LED Flash class devices as V4L2 sub-devices. The functions should
> be called from the LED subsystem device driver. In case the
> support for V4L2 Flash sub-devices is disabled in the kernel
> config the functions' empty versions will be used.
> 
> Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
> Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
> Cc: Sakari Ailus <sakari.ailus@iki.fi>
> Cc: Hans Verkuil <hans.verkuil@cisco.com>
> ---
> - fixed possible NULL fled_cdev pointer dereference
>   in the v4l2_flash_init function
> 
>  drivers/media/v4l2-core/Kconfig                |   11 +
>  drivers/media/v4l2-core/Makefile               |    2 +
>  drivers/media/v4l2-core/v4l2-flash-led-class.c |  710 ++++++++++++++++++++++++
>  include/media/v4l2-flash-led-class.h           |  148 +++++
>  4 files changed, 871 insertions(+)
>  create mode 100644 drivers/media/v4l2-core/v4l2-flash-led-class.c
>  create mode 100644 include/media/v4l2-flash-led-class.h
> 

<snip>

> diff --git a/drivers/media/v4l2-core/v4l2-flash-led-class.c b/drivers/media/v4l2-core/v4l2-flash-led-class.c
> new file mode 100644
> index 0000000..5bdfb8d
> --- /dev/null
> +++ b/drivers/media/v4l2-core/v4l2-flash-led-class.c

<snip>

> +static const struct v4l2_subdev_core_ops v4l2_flash_core_ops = {
> +	.queryctrl = v4l2_subdev_queryctrl,
> +	.querymenu = v4l2_subdev_querymenu,

Why are these here? This should not be necessary. As long as the sd.ctrl_handler
pointer is set, this is handled automatically.

> +};
> +
> +static const struct v4l2_subdev_ops v4l2_flash_subdev_ops = {
> +	.core = &v4l2_flash_core_ops,
> +};
> +

And if v4l2_flash_core_ops goes away, then this can go away as well.

I know this driver has been merged, but I just noticed this while looking at
something else.

Regards,

	Hans