[RFC] drm: atomic mode set API

[Jesse Barnes]

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;
+
+	__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?

Thanks,
Jesse