Hi Laurent.

On Sat, Apr 04, 2020 at 09:12:53PM +0300, Laurent Pinchart wrote:

The zpos property is used by userspace to sort the order of planes. While the property is not mandatory for drivers to implement, mixing planes with and without zpos confuses userspace, and shall not be allowed. Clarify this in the documentation and warn at runtime if the drivers mixes planes with and without zpos properties.

Signed-off-by: Laurent Pinchart laurent.pinchart+renesas@ideasonboard.com

Looks good. Acked-by: Sam Ravnborg sam@ravnborg.org

---

drivers/gpu/drm/drm_blend.c | 10 ++++++---- drivers/gpu/drm/drm_plane.c | 9 +++++++++ 2 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/drm_blend.c b/drivers/gpu/drm/drm_blend.c index 88eedee018d3..f1dcad96f341 100644 --- a/drivers/gpu/drm/drm_blend.c +++ b/drivers/gpu/drm/drm_blend.c @@ -135,7 +135,9 @@

• are underneath planes with higher Z position values. Two planes with the
• same Z position value have undefined ordering. Note that the Z position
• value can also be immutable, to inform userspace about the hard-coded

• • stacking of planes, see drm_plane_create_zpos_immutable_property().

• • stacking of planes, see drm_plane_create_zpos_immutable_property(). If
• • any plane has a zpos property (either mutable or immutable), then all
• • planes shall have a zpos property.
  • pixel blend mode:
  • Pixel blend mode is set up with drm_plane_create_blend_mode_property().

@@ -344,10 +346,10 @@ EXPORT_SYMBOL(drm_rotation_simplify);

• should be set to 0 and max to maximal number of planes for given crtc - 1.
• If zpos of some planes cannot be changed (like fixed background or

• • cursor/topmost planes), driver should adjust min/max values and assign those
• • planes immutable zpos property with lower or higher values (for more

• • cursor/topmost planes), drivers shall adjust the min/max values and assign
• • those planes immutable zpos properties with lower or higher values (for more
  • information, see drm_plane_create_zpos_immutable_property() function). In such

• • case driver should also assign proper initial zpos values for all planes in

• • case drivers shall also assign proper initial zpos values for all planes in
  • its plane_reset() callback, so the planes will be always sorted properly.
  • See also drm_atomic_normalize_zpos().

diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c index d6ad60ab0d38..efb9c16ddc21 100644 --- a/drivers/gpu/drm/drm_plane.c +++ b/drivers/gpu/drm/drm_plane.c @@ -289,6 +289,8 @@ EXPORT_SYMBOL(drm_universal_plane_init);

int drm_plane_register_all(struct drm_device *dev) {

• unsigned int num_planes = 0;
• unsigned int num_zpos = 0; struct drm_plane *plane; int ret = 0;

@@ -297,8 +299,15 @@ int drm_plane_register_all(struct drm_device *dev) ret = plane->funcs->late_register(plane); if (ret) return ret;

• if (plane->zpos_property)
  

• 	num_zpos++;
  

• num_planes++;
  

  }

• drm_WARN(dev, num_planes != num_zpos,

•  "Mixing planes with and without zpos property is invalid\n");
  

• return 0;

}

-- Regards,

Laurent Pinchart

---

dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel

On Sat, Apr 04, 2020 at 09:12:53PM +0300, Laurent Pinchart wrote:

The zpos property is used by userspace to sort the order of planes. While the property is not mandatory for drivers to implement, mixing planes with and without zpos confuses userspace, and shall not be allowed. Clarify this in the documentation and warn at runtime if the drivers mixes planes with and without zpos properties.

Signed-off-by: Laurent Pinchart laurent.pinchart+renesas@ideasonboard.com

drivers/gpu/drm/drm_blend.c | 10 ++++++---- drivers/gpu/drm/drm_plane.c | 9 +++++++++ 2 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/drm_blend.c b/drivers/gpu/drm/drm_blend.c index 88eedee018d3..f1dcad96f341 100644 --- a/drivers/gpu/drm/drm_blend.c +++ b/drivers/gpu/drm/drm_blend.c @@ -135,7 +135,9 @@

• are underneath planes with higher Z position values. Two planes with the
• same Z position value have undefined ordering. Note that the Z position
• value can also be immutable, to inform userspace about the hard-coded

• • stacking of planes, see drm_plane_create_zpos_immutable_property().

• • stacking of planes, see drm_plane_create_zpos_immutable_property(). If
• • any plane has a zpos property (either mutable or immutable), then all
• • planes shall have a zpos property.
  • pixel blend mode:
  • Pixel blend mode is set up with drm_plane_create_blend_mode_property().

@@ -344,10 +346,10 @@ EXPORT_SYMBOL(drm_rotation_simplify);

• should be set to 0 and max to maximal number of planes for given crtc - 1.
• If zpos of some planes cannot be changed (like fixed background or

• • cursor/topmost planes), driver should adjust min/max values and assign those
• • planes immutable zpos property with lower or higher values (for more

• • cursor/topmost planes), drivers shall adjust the min/max values and assign
• • those planes immutable zpos properties with lower or higher values (for more
  • information, see drm_plane_create_zpos_immutable_property() function). In such

• • case driver should also assign proper initial zpos values for all planes in

• • case drivers shall also assign proper initial zpos values for all planes in
  • its plane_reset() callback, so the planes will be always sorted properly.
  • See also drm_atomic_normalize_zpos().

diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c index d6ad60ab0d38..efb9c16ddc21 100644 --- a/drivers/gpu/drm/drm_plane.c +++ b/drivers/gpu/drm/drm_plane.c @@ -289,6 +289,8 @@ EXPORT_SYMBOL(drm_universal_plane_init);

int drm_plane_register_all(struct drm_device *dev) {

• unsigned int num_planes = 0;
• unsigned int num_zpos = 0; struct drm_plane *plane; int ret = 0;

@@ -297,8 +299,15 @@ int drm_plane_register_all(struct drm_device *dev) ret = plane->funcs->late_register(plane); if (ret) return ret;

• if (plane->zpos_property)
  

• 	num_zpos++;
  

• num_planes++;
  

  }

• drm_WARN(dev, num_planes != num_zpos,

0day spotted that you should change this to num_zpos && num_zpos == num_planes. Otherwise it doesn't really implement what you claim it does implement. With that fixed:

Reviewed-by: Daniel Vetter daniel.vetter@ffwll.ch

•  "Mixing planes with and without zpos property is invalid\n");
  

• return 0;

}

-- Regards,

Laurent Pinchart