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| author | Daniel Vetter <daniel.vetter@ffwll.ch> | 2019-09-06 17:44:59 +0300 |
|---|---|---|
| committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2019-09-06 21:23:21 +0300 |
| commit | 42770cbf18aefbe632f34e4097c872f1dca0ec4a (patch) | |
| tree | 2063637b3edb259abede7e9b799324769eb8891e /drivers/gpu/drm/drm_blend.c | |
| parent | c7581a414d28413c1dd6d116d44859b5a52e0950 (diff) | |
| download | linux-42770cbf18aefbe632f34e4097c872f1dca0ec4a.tar.xz | |
drm/blend: Define the direction of Z position values
We forgot that.
Proof is the one igt testcase we have:
https://gitlab.freedesktop.org/drm/igt-gpu-tools/blob/master/tests/kms_atomic.c#L280
While at it also document that we have immutable zpos properties in
some cases.
Reported-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Cc: Pekka Paalanen <pekka.paalanen@collabora.com>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Cc: Ilia Mirkin <imirkin@alum.mit.edu>
Acked-by: Ilia Mirkin <imirkin@alum.mit.edu>
Reviewed-by: Daniel Stone <daniels@collabora.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190906144459.16025-1-daniel.vetter@ffwll.ch
Diffstat (limited to 'drivers/gpu/drm/drm_blend.c')
| -rw-r--r-- | drivers/gpu/drm/drm_blend.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/gpu/drm/drm_blend.c b/drivers/gpu/drm/drm_blend.c index 37ac168fcb60..d02709dd2d4a 100644 --- a/drivers/gpu/drm/drm_blend.c +++ b/drivers/gpu/drm/drm_blend.c @@ -130,7 +130,12 @@ * Z position is set up with drm_plane_create_zpos_immutable_property() and * drm_plane_create_zpos_property(). It controls the visibility of overlapping * planes. Without this property the primary plane is always below the cursor - * plane, and ordering between all other planes is undefined. + * plane, and ordering between all other planes is undefined. The positive + * Z axis points towards the user, i.e. planes with lower Z position values + * are underneath planes with higher Z position values. Note that the Z + * position value can also be immutable, to inform userspace about the + * hard-coded stacking of overlay planes, see + * drm_plane_create_zpos_immutable_property(). * * pixel blend mode: * Pixel blend mode is set up with drm_plane_create_blend_mode_property(). |