[PATCH 3/3] drm: document minimum kernel version for DRM_CLIENT_CAP_*

[Daniel Vetter]

On Tue, May 18, 2021 at 11:14:52AM +0000, Simon Ser wrote:
> The kernel versions including the following commits are referenced:
> 
> DRM_CLIENT_CAP_STEREO_3D
> 61d8e3282541 ("drm: Add a STEREO_3D capability to the SET_CLIENT_CAP ioctl")
> 
> DRM_CLIENT_CAP_UNIVERSAL_PLANES
> 681e7ec73044 ("drm: Allow userspace to ask for universal plane list (v2)")
> c7dbc6c9ae5c ("drm: Remove command line guard for universal planes")
> 
> DRM_CLIENT_CAP_ATOMIC
> 88a48e297b3a ("drm: add atomic properties")
> 8b72ce158cf0 ("drm: Always enable atomic API")
> 
> DRM_CLIENT_CAP_ASPECT_RATIO
> 7595bda2fb43 ("drm: Add DRM client cap for aspect-ratio")
> 
> DRM_CLIENT_CAP_WRITEBACK_CONNECTORS
> d67b6a206507 ("drm: writeback: Add client capability for exposing writeback connectors")
> 
> Signed-off-by: Simon Ser <contact at emersion.fr>
> Cc: Daniel Vetter <daniel at ffwll.ch>
> Cc: Daniel Stone <daniels at collabora.com>
> Cc: Pekka Paalanen <ppaalanen at gmail.com>

On the series:

Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>

btw your threading is busted.
-Daniel
> ---
>  include/uapi/drm/drm.h | 17 +++++++++++++++++
>  1 file changed, 17 insertions(+)
> 
> diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h
> index 87878aea4526..ec2b122cdcc5 100644
> --- a/include/uapi/drm/drm.h
> +++ b/include/uapi/drm/drm.h
> @@ -780,6 +780,8 @@ struct drm_get_cap {
>   * If set to 1, the DRM core will expose the stereo 3D capabilities of the
>   * monitor by advertising the supported 3D layouts in the flags of struct
>   * drm_mode_modeinfo. See ``DRM_MODE_FLAG_3D_*``.
> + *
> + * This capability is always supported starting from kernel version 3.13.
>   */
>  #define DRM_CLIENT_CAP_STEREO_3D	1
>  
> @@ -788,6 +790,9 @@ struct drm_get_cap {
>   *
>   * If set to 1, the DRM core will expose all planes (overlay, primary, and
>   * cursor) to userspace.
> + *
> + * This capability has been introduced in kernel version 3.15. Starting from
> + * kernel version 3.17, this capability is always supported.
>   */
>  #define DRM_CLIENT_CAP_UNIVERSAL_PLANES  2
>  
> @@ -797,6 +802,13 @@ struct drm_get_cap {
>   * If set to 1, the DRM core will expose atomic properties to userspace. This
>   * implicitly enables &DRM_CLIENT_CAP_UNIVERSAL_PLANES and
>   * &DRM_CLIENT_CAP_ASPECT_RATIO.
> + *
> + * If the driver doesn't support atomic mode-setting, enabling this capability
> + * will fail with -EOPNOTSUPP.
> + *
> + * This capability has been introduced in kernel version 4.0. Starting from
> + * kernel version 4.2, this capability is always supported for atomic-capable
> + * drivers.
>   */
>  #define DRM_CLIENT_CAP_ATOMIC	3
>  
> @@ -805,6 +817,8 @@ struct drm_get_cap {
>   *
>   * If set to 1, the DRM core will provide aspect ratio information in modes.
>   * See ``DRM_MODE_FLAG_PIC_AR_*``.
> + *
> + * This capability is always supported starting from kernel version 4.18.
>   */
>  #define DRM_CLIENT_CAP_ASPECT_RATIO    4
>  
> @@ -814,6 +828,9 @@ struct drm_get_cap {
>   * If set to 1, the DRM core will expose special connectors to be used for
>   * writing back to memory the scene setup in the commit. The client must enable
>   * &DRM_CLIENT_CAP_ATOMIC first.
> + *
> + * This capability is always supported for atomic-capable drivers starting from
> + * kernel version 4.19.
>   */
>  #define DRM_CLIENT_CAP_WRITEBACK_CONNECTORS	5
>  
> -- 
> 2.31.1
> 
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch