From: Thierry Reding treding@nvidia.com
As of commit 4dc55525b095 ("drm: plane: Verify that no or all planes have a zpos property") a warning is emitted if there's a mix of planes with and without a zpos property.
On Tegra, cursor planes are always composited on top of all other planes, which is why they never had a zpos property attached to them. However, since the composition order is fixed, this is trivial to remedy by simply attaching an immutable zpos property to them.
Reported-by: Jonathan Hunter jonathanh@nvidia.com Signed-off-by: Thierry Reding treding@nvidia.com --- drivers/gpu/drm/tegra/dc.c | 10 ++++++++-- drivers/gpu/drm/tegra/hub.c | 2 +- 2 files changed, 9 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/tegra/dc.c b/drivers/gpu/drm/tegra/dc.c index 83f31c6e891c..e7a6eb952ece 100644 --- a/drivers/gpu/drm/tegra/dc.c +++ b/drivers/gpu/drm/tegra/dc.c @@ -787,7 +787,7 @@ static struct drm_plane *tegra_primary_plane_create(struct drm_device *drm, }
drm_plane_helper_add(&plane->base, &tegra_plane_helper_funcs); - drm_plane_create_zpos_property(&plane->base, plane->index, 0, 255); + drm_plane_create_zpos_property(&plane->base, 1 + plane->index, 1, 255);
err = drm_plane_create_rotation_property(&plane->base, DRM_MODE_ROTATE_0, @@ -957,6 +957,7 @@ static struct drm_plane *tegra_dc_cursor_plane_create(struct drm_device *drm, }
drm_plane_helper_add(&plane->base, &tegra_cursor_plane_helper_funcs); + drm_plane_create_zpos_immutable_property(&plane->base, 0);
return &plane->base; } @@ -1074,7 +1075,12 @@ static struct drm_plane *tegra_dc_overlay_plane_create(struct drm_device *drm, }
drm_plane_helper_add(&plane->base, &tegra_plane_helper_funcs); - drm_plane_create_zpos_property(&plane->base, plane->index, 0, 255); + + if (!cursor) + drm_plane_create_zpos_property(&plane->base, 1 + plane->index, + 1, 255); + else + drm_plane_create_zpos_immutable_property(&plane->base, 0);
err = drm_plane_create_rotation_property(&plane->base, DRM_MODE_ROTATE_0, diff --git a/drivers/gpu/drm/tegra/hub.c b/drivers/gpu/drm/tegra/hub.c index a2ef8f218d4e..697d75bbb9fa 100644 --- a/drivers/gpu/drm/tegra/hub.c +++ b/drivers/gpu/drm/tegra/hub.c @@ -590,7 +590,7 @@ struct drm_plane *tegra_shared_plane_create(struct drm_device *drm, }
drm_plane_helper_add(p, &tegra_shared_plane_helper_funcs); - drm_plane_create_zpos_property(p, 0, 0, 255); + drm_plane_create_zpos_property(p, 1 + index, 1, 255);
return p; }
Hi Dmitry,
On Thu, 11 Jun 2020 at 08:54, Dmitry Osipenko digetx@gmail.com wrote:
Well, it fixes the WARN_ON, which asserts that either no planes have the zpos property attached, or all planes have the zpos property attached. When only _some_ planes have the property, the property is pretty much useless: zpos exists to guarantee to userspace the relative ordering between planes, defined by the value of the property. If not all planes have the property, then userspace cannot reason about the ordering, since some of the planes have undefined ordering.
Cheers, Daniel
11.06.2020 11:17, Daniel Stone пишет:
Hello Daniel,
So it's a kernel warning, thank you for the clarification! I'm running only older Tegras that have a black-n-white cursor plane, but this is not supported by the upstream kernel. No wonder that I haven't seen the warning, this made me curious what this patch is about :)
dri-devel@lists.freedesktop.org
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Daniel Stone -
Dmitry Osipenko -
Thierry Reding -
Ville Syrjälä