Nouveau - Jun 2024 - [PATCH v7 5/9] drm/i915: Enable async flips on the primary plane

Allow userspace to use explicit synchronization with atomic async flips.
That means that the flip will wait for some hardware fence, and then
will flip as soon as possible (async) in regard of the vblank.

Signed-off-by: Andr? Almeida <andrealmeid at igalia.com>
---
 drivers/gpu/drm/drm_atomic_uapi.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_atomic_uapi.c
b/drivers/gpu/drm/drm_atomic_uapi.c
index 22bbb2d83e30..2e1d9391febe 100644
--- a/drivers/gpu/drm/drm_atomic_uapi.c
+++ b/drivers/gpu/drm/drm_atomic_uapi.c
@@ -1070,7 +1070,9 @@ int drm_atomic_set_property(struct drm_atomic_state
*state,
 			break;
 		}
 
-		if (async_flip && prop != config->prop_fb_id) {
+		if (async_flip &&
+		    prop != config->prop_fb_id &&
+		    prop != config->prop_in_fence_fd) {
 			ret = drm_atomic_plane_get_property(plane, plane_state,
 							    prop, &old_val);
 			ret = drm_atomic_check_prop_changes(ret, old_val, prop_value, prop);
-- 
2.45.2

AMD hardware can do async flips with overlay planes, but currently there's
no
easy way to enable that in DRM. To solve that, this patchset creates a new
drm_plane field, bool async_flip, that allows drivers to choose which plane can
or cannot do async flips. This is latter used on drm_atomic_set_property when
users want to do async flips.

Patch 1 allows async commits with IN_FENCE_ID in any driver.

Patches 2 to 7 have no functional change. As per current code, every driver that
allows async page flips using the atomic API, allows doing it only in the
primary plane. Those patches then enable it for every driver.

Every driver that I found out capable of doing async flips were changed here.
The drivers that weren't touch don't have any mention to
mode_config::async_page_flip, so they are not currently advertising to userspace
that they can do async flips.

Patch 8 changes the current DRM uAPI check from allowing only primary planes to
allowing any plane that the driver allows flipping asynchronously.

Patch 9 finally enables async flip on overlay planes for amdgpu.

Changes from v6:
- Added async_flip check for i915/skl planes (Rodrigo)
- Commit the plane->async_flip check just after all driver had set their
async_flip capabilities (Dmitry)
https://lore.kernel.org/dri-devel/20240614153535.351689-1-andrealmeid at
igalia.com/

Changes from v5:
- Instead of enabling plane->async_flip in the common code, move it to driver
code.
- Enable primary plane async flip on every driver
https://lore.kernel.org/dri-devel/20240612193713.167448-1-andrealmeid at
igalia.com/

Andr? Almeida (9):
  drm/atomic: Allow userspace to use explicit sync with atomic async
    flips
  drm: Support per-plane async flip configuration
  drm/amdgpu: Enable async flips on the primary plane
  drm: atmel-hlcdc: Enable async flips on the primary plane
  drm/i915: Enable async flips on the primary plane
  drm/nouveau: Enable async flips on the primary plane
  drm/vc4: Enable async flips on the primary plane
  drm: Enable per-plane async flip check
  drm/amdgpu: Make it possible to async flip overlay planes

 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c | 2 ++
 drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c         | 3 +++
 drivers/gpu/drm/drm_atomic_uapi.c                       | 8 +++++---
 drivers/gpu/drm/i915/display/i9xx_plane.c               | 3 +++
 drivers/gpu/drm/i915/display/skl_universal_plane.c      | 1 +
 drivers/gpu/drm/nouveau/dispnv04/crtc.c                 | 4 ++++
 drivers/gpu/drm/nouveau/dispnv50/wndw.c                 | 4 ++++
 drivers/gpu/drm/vc4/vc4_plane.c                         | 4 +++-
 include/drm/drm_plane.h                                 | 5 +++++
 9 files changed, 30 insertions(+), 4 deletions(-)

-- 
2.45.2

Drivers have different capabilities on what plane types they can or
cannot perform async flips. Create a plane::async_flip field so each
driver can choose which planes they allow doing async flips.

Signed-off-by: Andr? Almeida <andrealmeid at igalia.com>
---
 include/drm/drm_plane.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/include/drm/drm_plane.h b/include/drm/drm_plane.h
index 9507542121fa..0bebc72af5c3 100644
--- a/include/drm/drm_plane.h
+++ b/include/drm/drm_plane.h
@@ -786,6 +786,11 @@ struct drm_plane {
 	 * @kmsg_panic: Used to register a panic notifier for this plane
 	 */
 	struct kmsg_dumper kmsg_panic;
+
+	/**
+	 * @async_flip: indicates if a plane can do async flips
+	 */
+	bool async_flip;
 };
 
 #define obj_to_plane(x) container_of(x, struct drm_plane, base)
-- 
2.45.2

This driver can perfom async flips on primary planes, so enable it.

Signed-off-by: Andr? Almeida <andrealmeid at igalia.com>
---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c
b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c
index 8a4c40b4c27e..0c126c5609d3 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c
@@ -1705,6 +1705,7 @@ int amdgpu_dm_plane_init(struct amdgpu_display_manager
*dm,
 
 	if (plane->type == DRM_PLANE_TYPE_PRIMARY) {
 		drm_plane_create_zpos_immutable_property(plane, 0);
+		plane->async_flip = true;
 	} else if (plane->type == DRM_PLANE_TYPE_OVERLAY) {
 		unsigned int zpos = 1 + drm_plane_index(plane);
 		drm_plane_create_zpos_property(plane, zpos, 1, 254);
-- 
2.45.2

This driver can perfom async flips on primary planes, so enable it.

Signed-off-by: Andr? Almeida <andrealmeid at igalia.com>
---
 drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c
b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c
index 4a7ba0918eca..22b8a5c888ef 100644
--- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c
+++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c
@@ -1227,6 +1227,9 @@ static int atmel_hlcdc_plane_create(struct drm_device
*dev,
 	if (ret)
 		return ret;
 
+	if (type == DRM_PLANE_TYPE_PRIMARY)
+		plane->base.async_flip = true;
+
 	drm_plane_helper_add(&plane->base,
 			     &atmel_hlcdc_layer_plane_helper_funcs);
 
-- 
2.45.2

This driver can perfom async flips on primary planes, so enable it.

Signed-off-by: Andr? Almeida <andrealmeid at igalia.com>
---
 drivers/gpu/drm/i915/display/i9xx_plane.c          | 3 +++
 drivers/gpu/drm/i915/display/skl_universal_plane.c | 1 +
 2 files changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/i9xx_plane.c
b/drivers/gpu/drm/i915/display/i9xx_plane.c
index 0279c8aabdd1..0142beef20dc 100644
--- a/drivers/gpu/drm/i915/display/i9xx_plane.c
+++ b/drivers/gpu/drm/i915/display/i9xx_plane.c
@@ -931,6 +931,9 @@ intel_primary_plane_create(struct drm_i915_private
*dev_priv, enum pipe pipe)
 
 	intel_plane_helper_add(plane);
 
+	if (plane->async_flip)
+		plane->base.async_flip = true;
+
 	return plane;
 
 fail:
diff --git a/drivers/gpu/drm/i915/display/skl_universal_plane.c
b/drivers/gpu/drm/i915/display/skl_universal_plane.c
index 860574d04f88..8d0a9f69709a 100644
--- a/drivers/gpu/drm/i915/display/skl_universal_plane.c
+++ b/drivers/gpu/drm/i915/display/skl_universal_plane.c
@@ -2371,6 +2371,7 @@ skl_universal_plane_create(struct drm_i915_private
*dev_priv,
 		plane->async_flip = skl_plane_async_flip;
 		plane->enable_flip_done = skl_plane_enable_flip_done;
 		plane->disable_flip_done = skl_plane_disable_flip_done;
+		plane->base.async_flip = true;
 	}
 
 	if (DISPLAY_VER(dev_priv) >= 11)
-- 
2.45.2

This driver can perfom async flips on primary planes, so enable it.

Signed-off-by: Andr? Almeida <andrealmeid at igalia.com>
---
 drivers/gpu/drm/nouveau/dispnv04/crtc.c | 4 ++++
 drivers/gpu/drm/nouveau/dispnv50/wndw.c | 4 ++++
 2 files changed, 8 insertions(+)

diff --git a/drivers/gpu/drm/nouveau/dispnv04/crtc.c
b/drivers/gpu/drm/nouveau/dispnv04/crtc.c
index 4310ad71870b..fd06d46d49ec 100644
--- a/drivers/gpu/drm/nouveau/dispnv04/crtc.c
+++ b/drivers/gpu/drm/nouveau/dispnv04/crtc.c
@@ -1285,6 +1285,7 @@ int
 nv04_crtc_create(struct drm_device *dev, int crtc_num)
 {
 	struct nouveau_display *disp = nouveau_display(dev);
+	struct nouveau_drm *drm = nouveau_drm(dev);
 	struct nouveau_crtc *nv_crtc;
 	struct drm_plane *primary;
 	int ret;
@@ -1338,6 +1339,9 @@ nv04_crtc_create(struct drm_device *dev, int crtc_num)
 	if (ret)
 		return ret;
 
+	if (drm->client.device.info.chipset >= 0x11)
+		primary->async_flip = true;
+
 	return nvif_head_vblank_event_ctor(&nv_crtc->head, "kmsVbl",
nv04_crtc_vblank_handler,
 					   false, &nv_crtc->vblank);
 }
diff --git a/drivers/gpu/drm/nouveau/dispnv50/wndw.c
b/drivers/gpu/drm/nouveau/dispnv50/wndw.c
index 7a2cceaee6e9..55db0fdf61e7 100644
--- a/drivers/gpu/drm/nouveau/dispnv50/wndw.c
+++ b/drivers/gpu/drm/nouveau/dispnv50/wndw.c
@@ -763,6 +763,10 @@ nv50_wndw_new_(const struct nv50_wndw_func *func, struct
drm_device *dev,
 			return ret;
 	}
 
+	if (type == DRM_PLANE_TYPE_PRIMARY &&
+	    drm->client.device.info.chipset >= 0x11)
+		wndw->plane.async_flip = true;
+
 	return 0;
 }
 
-- 
2.45.2

This driver can perfom async flips on primary planes, so enable it.

Signed-off-by: Andr? Almeida <andrealmeid at igalia.com>
---
 drivers/gpu/drm/vc4/vc4_plane.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/vc4/vc4_plane.c b/drivers/gpu/drm/vc4/vc4_plane.c
index 07caf2a47c6c..e3d41da14e6f 100644
--- a/drivers/gpu/drm/vc4/vc4_plane.c
+++ b/drivers/gpu/drm/vc4/vc4_plane.c
@@ -1672,8 +1672,10 @@ struct drm_plane *vc4_plane_init(struct drm_device *dev,
 					  DRM_COLOR_YCBCR_BT709,
 					  DRM_COLOR_YCBCR_LIMITED_RANGE);
 
-	if (type == DRM_PLANE_TYPE_PRIMARY)
+	if (type == DRM_PLANE_TYPE_PRIMARY) {
 		drm_plane_create_zpos_immutable_property(plane, 0);
+		plane->async_flip = true;
+	}
 
 	return plane;
 }
-- 
2.45.2

Replace the generic "is this plane primary" for a plane::async_flip
check, so DRM follows the plane restrictions set by the driver.

Signed-off-by: Andr? Almeida <andrealmeid at igalia.com>
---
 drivers/gpu/drm/drm_atomic_uapi.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/drm_atomic_uapi.c
b/drivers/gpu/drm/drm_atomic_uapi.c
index 2e1d9391febe..ed1af3455477 100644
--- a/drivers/gpu/drm/drm_atomic_uapi.c
+++ b/drivers/gpu/drm/drm_atomic_uapi.c
@@ -1079,9 +1079,9 @@ int drm_atomic_set_property(struct drm_atomic_state
*state,
 			break;
 		}
 
-		if (async_flip && plane_state->plane->type !=
DRM_PLANE_TYPE_PRIMARY) {
+		if (async_flip && !plane->async_flip) {
 			drm_dbg_atomic(prop->dev,
-				       "[OBJECT:%d] Only primary planes can be changed during async
flip\n",
+				       "[PLANE:%d] does not support async flips\n",
 				       obj->id);
 			ret = -EINVAL;
 			break;
-- 
2.45.2

amdgpu can handle async flips on overlay planes, so mark it as true
during the plane initialization.

Signed-off-by: Andr? Almeida <andrealmeid at igalia.com>
---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c
b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c
index 0c126c5609d3..7d508d816f0d 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c
@@ -1709,6 +1709,7 @@ int amdgpu_dm_plane_init(struct amdgpu_display_manager
*dm,
 	} else if (plane->type == DRM_PLANE_TYPE_OVERLAY) {
 		unsigned int zpos = 1 + drm_plane_index(plane);
 		drm_plane_create_zpos_property(plane, zpos, 1, 254);
+		plane->async_flip = true;
 	} else if (plane->type == DRM_PLANE_TYPE_CURSOR) {
 		drm_plane_create_zpos_immutable_property(plane, 255);
 	}
-- 
2.45.2

On Tue, 18 Jun 2024, Andr? Almeida <andrealmeid at igalia.com>
wrote:
> Drivers have different capabilities on what plane types they can or
> cannot perform async flips. Create a plane::async_flip field so each
> driver can choose which planes they allow doing async flips.
>
> Signed-off-by: Andr? Almeida <andrealmeid at igalia.com>
> ---
>  include/drm/drm_plane.h | 5 +++++
>  1 file changed, 5 insertions(+)
>
> diff --git a/include/drm/drm_plane.h b/include/drm/drm_plane.h
> index 9507542121fa..0bebc72af5c3 100644
> --- a/include/drm/drm_plane.h
> +++ b/include/drm/drm_plane.h
> @@ -786,6 +786,11 @@ struct drm_plane {
>  	 * @kmsg_panic: Used to register a panic notifier for this plane
>  	 */
>  	struct kmsg_dumper kmsg_panic;
> +
> +	/**
> +	 * @async_flip: indicates if a plane can do async flips
> +	 */
When is it okay to set or change the value of this member?

If you don't document it, people will find creative uses for this.

BR,
Jani.

> +	bool async_flip;
>  };
>  
>  #define obj_to_plane(x) container_of(x, struct drm_plane, base)
-- 
Jani Nikula, Intel