[RFC] drm: atomic mode set API

[Jakob Bornecrantz]

----- Original Message -----
> Many of us really want (and need) a way to set the whole display
> configuration atomically, as well as test a global config.
> 
> In talking with Rob and Alex here at ELC a bit, I think this may be
> enough:
> 
> diff --git a/include/drm/drm_mode.h b/include/drm/drm_mode.h
> index 2a2acda..2864b02 100644
> --- a/include/drm/drm_mode.h
> +++ b/include/drm/drm_mode.h
> @@ -157,6 +157,26 @@ struct drm_mode_get_plane_res {
>  	__u32 count_planes;
>  };
>  
> +#define DRM_SET_CONFIG_TEST (1<<0) /* don't change the config, just test it for validity */
> +
> +struct drm_mode_set_config {
> +	__u64 crtcs;
> +	__u64 crtc_fbs;
> +	__u64 crtc_xpos; /* array of x coords for crtcs */
> +	__u64 crtc_ypos; /* array of y coords for crtcs */
> +	__u32 count_crtcs;
> +
> +	__u64 plane_sets; /* array of set_plane structs */
> +
> +	__u32 count_planes;
> +
> +	__u64 connectors;
> +	__u64 connector_modes;
> +	__u32 count_connectors;

How do you do mirroring? Why not just send down a array of
drm_mode_crtc?

> +
> +	__u32 flags;
> +};
> +
>  #define DRM_MODE_ENCODER_NONE	0
>  #define DRM_MODE_ENCODER_DAC	1
>  #define DRM_MODE_ENCODER_TMDS	2
> 
> This allows you to bind a bunch of fbs to crtcs with independent
> positions, as well as set a bunch of planes to specific fbs and
> layouts.  Finally, it lets you change the connector config at the
> same time, with a flag to simply test a config instead of
> actually setting it.
> 
> Any comments?  Do we also need to set gamma or other properties as
> part of this?  What about cursors?

I would like to see properties added as well.

Cheers, Jakob.