Re: [PATCH 2/9 v9] V4L: add two new ioctl()s for multi-size videobuffer management

[Sakari Ailus <sakari.ailus@iki.fi>]

Guennadi Liakhovetski wrote:
> A possibility to preallocate and initialise buffers of different sizes
> in V4L2 is required for an efficient implementation of a snapshot
> mode. This patch adds two new ioctl()s: VIDIOC_CREATE_BUFS and
> VIDIOC_PREPARE_BUF and defines respective data structures.
> 
> Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>

Hi Guennadi,

Thanks for the patch and your tireless efforts on this!

VIDIOC_PREPARE_BUF is actually _IOW (rather than _IOWR) in this patch. I
guess it shouldn't be this way, or have I failed to understand
something? :-)

[clip]

> @@ -2189,6 +2202,11 @@ struct v4l2_dbg_chip_ident {
>  #define	VIDIOC_SUBSCRIBE_EVENT	 _IOW('V', 90, struct v4l2_event_subscription)
>  #define	VIDIOC_UNSUBSCRIBE_EVENT _IOW('V', 91, struct v4l2_event_subscription)
>  
> +/* Experimental, the below two ioctls may change over the next couple of kernel
> +   versions */
> +#define VIDIOC_CREATE_BUFS	_IOWR('V', 92, struct v4l2_create_buffers)
> +#define VIDIOC_PREPARE_BUF	 _IOW('V', 93, struct v4l2_buffer)
> +
>  /* Reminder: when adding new ioctls please add support for them to
>     drivers/media/video/v4l2-compat-ioctl32.c as well! */
>  


-- 
Sakari Ailus
sakari.ailus@iki.fi