From: Tomi Valkeinen tomi.valkeinen@ideasonboard.com
[ Upstream commit 3ec948ccb2c4b99e8fbfdd950adbe92ea577b395 ]
When the driver sets up the zpos property it sets the default zpos value to the HW id of the plane. That is fine as such, but as on many DSS versions the driver arranges the DRM planes in a different order than the HW planes (to keep the non-scalable planes first), this leads to odd initial zpos values. An example is J721e, where the initial zpos values for DRM planes are 1, 3, 0, 2.
In theory the userspace should configure the zpos values properly when using multiple planes, and in that sense the initial zpos values shouldn't matter, but there's really no reason not to fix this and help the userspace apps which don't handle zpos perfectly. In particular, some versions of Weston seem to have issues dealing with the planes with the current default zpos values.
So let's change the zpos values for the DRM planes to 0, 1, 2, 3.
Another option would be to configure the planes marked as primary planes to zpos 0. On a two display system this would give us plane zpos values of 0, 0, 1, 2. The end result and behavior would be very similar in this option, and I'm not aware that this would actually help us in any way. So, to keep the code simple, I opted for the 0, 1, 2, 3 values.
Fixes: 32a1795f57ee ("drm/tidss: New driver for TI Keystone platform Display SubSystem") Reviewed-by: Aradhya Bhatia a-bhatia1@ti.com Signed-off-by: Tomi Valkeinen tomi.valkeinen@ideasonboard.com Link: https://patchwork.freedesktop.org/patch/msgid/20240213-tidss-fixes-v1-1-d709... Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/tidss/tidss_plane.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/tidss/tidss_plane.c b/drivers/gpu/drm/tidss/tidss_plane.c index 217415ec8eea1..8ccd7d31c01b3 100644 --- a/drivers/gpu/drm/tidss/tidss_plane.c +++ b/drivers/gpu/drm/tidss/tidss_plane.c @@ -210,7 +210,7 @@ struct tidss_plane *tidss_plane_create(struct tidss_device *tidss,
drm_plane_helper_add(&tplane->plane, &tidss_plane_helper_funcs);
- drm_plane_create_zpos_property(&tplane->plane, hw_plane_id, 0, + drm_plane_create_zpos_property(&tplane->plane, tidss->num_planes, 0, num_planes - 1);
ret = drm_plane_create_color_properties(&tplane->plane,