All of lore.kernel.org
 help / color / mirror / Atom feed
From: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
To: dri-devel@lists.freedesktop.org
Cc: linux-renesas-soc@vger.kernel.org
Subject: [PATCH v2] drm: plane: Verify that no or all planes have a zpos property
Date: Thu, 14 May 2020 01:58:35 +0300	[thread overview]
Message-ID: <20200513225835.19361-1-laurent.pinchart+renesas@ideasonboard.com> (raw)

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>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
---
Changes since v1:

- Fix verification when no planes have a zpos property
---
 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..4af173ced327 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_zpos && num_planes != num_zpos,
+		 "Mixing planes with and without zpos property is invalid\n");
+
 	return 0;
 }
 
-- 
Regards,

Laurent Pinchart


WARNING: multiple messages have this Message-ID
From: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
To: dri-devel@lists.freedesktop.org
Cc: linux-renesas-soc@vger.kernel.org
Subject: [PATCH v2] drm: plane: Verify that no or all planes have a zpos property
Date: Thu, 14 May 2020 01:58:35 +0300	[thread overview]
Message-ID: <20200513225835.19361-1-laurent.pinchart+renesas@ideasonboard.com> (raw)

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>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
---
Changes since v1:

- Fix verification when no planes have a zpos property
---
 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..4af173ced327 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_zpos && 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

             reply	other threads:[~2020-05-13 22:58 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-13 22:58 Laurent Pinchart [this message]
2020-05-13 22:58 ` [PATCH v2] drm: plane: Verify that no or all planes have a zpos property Laurent Pinchart
2020-05-14  6:36 ` Simon Ser
2020-05-14  6:36   ` Simon Ser

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200513225835.19361-1-laurent.pinchart+renesas@ideasonboard.com \
    --to=laurent.pinchart+renesas@ideasonboard.com \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=linux-renesas-soc@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.