drm/v3d: Add some better documentation of the in_sync arguments.

Since this is UAPI, it's good to document what exactly the guarantees
we're providing are.

Signed-off-by: Eric Anholt <eric@anholt.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20180928232126.4332-3-eric@anholt.net
Reviewed-by: Boris Brezillon <boris.brezillon@bootlin.com>

diff --git a/include/uapi/drm/v3d_drm.h b/include/uapi/drm/v3d_drm.h
index 7b6627783608edb92cc6fbfe7c9932a5766e6e8b..f446656d00b1d335cdfd767c1aa2336e06a54d33 100644 (file)
--- a/include/uapi/drm/v3d_drm.h
+++ b/include/uapi/drm/v3d_drm.h
@@ -58,6 +58,11 @@ struct drm_v3d_submit_cl {
         * coordinate shader to determine where primitives land on the screen,
         * then writes out the state updates and draw calls necessary per tile
         * to the tile allocation BO.
+        *
+        * This BCL will block on any previous BCL submitted on the
+        * same FD, but not on any RCL or BCLs submitted by other
+        * clients -- that is left up to the submitter to control
+        * using in_sync_bcl if necessary.
         */
        __u32 bcl_start;
 
@@ -69,6 +74,11 @@ struct drm_v3d_submit_cl {
         * This is the second set of commands executed, which will either
         * execute the tiles that have been set up by the BCL, or a fixed set
         * of tiles (in the case of RCL-only blits).
+        *
+        * This RCL will block on this submit's BCL, and any previous
+        * RCL submitted on the same FD, but not on any RCL or BCLs
+        * submitted by other clients -- that is left up to the
+        * submitter to control using in_sync_rcl if necessary.
         */
        __u32 rcl_start;