[PATCH v4 01/10] drm/damage-helper: Do not alter damage clips on modeset, but ignore them

[PATCH v4 01/10] drm/damage-helper: Do not alter damage clips on modeset, but ignore them

[Thomas Zimmermann]

User space supplies rectangles for damage clipping in a plane property.
For full mode sets, drivers still require a full plane update. In this
case, leave the information as-is and set the ignore_damage_clips flag
instead. The damage iterator will later ignore any damage information.

Also fixes a bug where ignore_damage_clips was not cleared across plane-
state duplications.

Leaving the damage information as-is might be helpful to drivers that
benefit from this information even on full modesets (e.g., for cache
management). It will also help with consolidating the damage-handling
logic.

Also add a new unit test that evaluates the ignore_damage_clips flag. It
sets two damage clips plus the flag and tests if the reported damage
covers the entire framebuffer.

v4:
- slightly reword the commit description

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Fixes: 35ed38d58257 ("drm: Allow drivers to indicate the damage helpers to ignore damage clips")
Acked-by: Zack Rusin <zack.rusin@broadcom.com>
Cc: dri-devel@lists.freedesktop.org
Cc: <stable@vger.kernel.org> # v6.10+
---
 drivers/gpu/drm/drm_atomic_state_helper.c     |  1 +
 drivers/gpu/drm/drm_damage_helper.c           |  6 ++--
 .../gpu/drm/tests/drm_damage_helper_test.c    | 28 +++++++++++++++++++
 3 files changed, 31 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/drm_atomic_state_helper.c b/drivers/gpu/drm/drm_atomic_state_helper.c
index cc70508d4fdb..84d5231ccac1 100644
--- a/drivers/gpu/drm/drm_atomic_state_helper.c
+++ b/drivers/gpu/drm/drm_atomic_state_helper.c
@@ -359,6 +359,7 @@ void __drm_atomic_helper_plane_duplicate_state(struct drm_plane *plane,
 	state->fence = NULL;
 	state->commit = NULL;
 	state->fb_damage_clips = NULL;
+	state->ignore_damage_clips = false;
 	state->color_mgmt_changed = false;
 }
 EXPORT_SYMBOL(__drm_atomic_helper_plane_duplicate_state);
diff --git a/drivers/gpu/drm/drm_damage_helper.c b/drivers/gpu/drm/drm_damage_helper.c
index 74a7f4252ecf..945fac8dc27b 100644
--- a/drivers/gpu/drm/drm_damage_helper.c
+++ b/drivers/gpu/drm/drm_damage_helper.c
@@ -78,10 +78,8 @@ void drm_atomic_helper_check_plane_damage(struct drm_atomic_commit *state,
 		if (WARN_ON(!crtc_state))
 			return;
 
-		if (drm_atomic_crtc_needs_modeset(crtc_state)) {
-			drm_property_blob_put(plane_state->fb_damage_clips);
-			plane_state->fb_damage_clips = NULL;
-		}
+		if (drm_atomic_crtc_needs_modeset(crtc_state))
+			plane_state->ignore_damage_clips = true;
 	}
 }
 EXPORT_SYMBOL(drm_atomic_helper_check_plane_damage);
diff --git a/drivers/gpu/drm/tests/drm_damage_helper_test.c b/drivers/gpu/drm/tests/drm_damage_helper_test.c
index 0df2e1a54b0d..64f038a62ffe 100644
--- a/drivers/gpu/drm/tests/drm_damage_helper_test.c
+++ b/drivers/gpu/drm/tests/drm_damage_helper_test.c
@@ -603,6 +603,33 @@ static void drm_test_damage_iter_damage_not_visible(struct kunit *test)
 	KUNIT_EXPECT_EQ_MSG(test, num_hits, 0, "Should not return any damage.");
 }
 
+static void drm_test_damage_iter_damage_ignore(struct kunit *test)
+{
+	struct drm_damage_mock *mock = test->priv;
+	struct drm_atomic_helper_damage_iter iter;
+	struct drm_property_blob damage_blob;
+	struct drm_mode_rect damage[2];
+	struct drm_rect clip;
+	u32 num_hits = 0;
+
+	set_plane_src(&mock->old_state, 0, 0, 1024 << 16, 768 << 16);
+	set_plane_src(&mock->state, 0, 0, 1024 << 16, 768 << 16);
+	/* 2 damage clips, but ignore them. */
+	set_damage_clip(&damage[0], 20, 30, 200, 180);
+	set_damage_clip(&damage[1], 240, 200, 280, 250);
+	set_damage_blob(&damage_blob, &damage[0], sizeof(damage));
+	set_plane_damage(&mock->state, &damage_blob);
+	mock->state.ignore_damage_clips = true;
+	drm_atomic_helper_damage_iter_init(&iter, &mock->old_state, &mock->state);
+	drm_atomic_for_each_plane_damage(&iter, &clip) {
+		if (num_hits == 0)
+			check_damage_clip(test, &clip, 0, 0, 1024, 768);
+		num_hits++;
+	}
+
+	KUNIT_EXPECT_EQ_MSG(test, num_hits, 1, "Should return full-framebuffer damage.");
+}
+
 static struct kunit_case drm_damage_helper_tests[] = {
 	KUNIT_CASE(drm_test_damage_iter_no_damage),
 	KUNIT_CASE(drm_test_damage_iter_no_damage_fractional_src),
@@ -625,6 +652,7 @@ static struct kunit_case drm_damage_helper_tests[] = {
 	KUNIT_CASE(drm_test_damage_iter_damage_one_outside),
 	KUNIT_CASE(drm_test_damage_iter_damage_src_moved),
 	KUNIT_CASE(drm_test_damage_iter_damage_not_visible),
+	KUNIT_CASE(drm_test_damage_iter_damage_ignore),
 	{ }
 };
 
-- 
2.54.0

Re: [PATCH v4 01/10] drm/damage-helper: Do not alter damage clips on modeset, but ignore them

[Javier Martinez Canillas]

Thomas Zimmermann <tzimmermann@suse.de> writes:

Hello Thomas,

> User space supplies rectangles for damage clipping in a plane property.
> For full mode sets, drivers still require a full plane update. In this
> case, leave the information as-is and set the ignore_damage_clips flag
> instead. The damage iterator will later ignore any damage information.
>
> Also fixes a bug where ignore_damage_clips was not cleared across plane-
> state duplications.
>
> Leaving the damage information as-is might be helpful to drivers that
> benefit from this information even on full modesets (e.g., for cache
> management). It will also help with consolidating the damage-handling
> logic.
>
> Also add a new unit test that evaluates the ignore_damage_clips flag. It
> sets two damage clips plus the flag and tests if the reported damage
> covers the entire framebuffer.
>
> v4:
> - slightly reword the commit description
>
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> Fixes: 35ed38d58257 ("drm: Allow drivers to indicate the damage helpers to ignore damage clips")
> Acked-by: Zack Rusin <zack.rusin@broadcom.com>
> Cc: dri-devel@lists.freedesktop.org
> Cc: <stable@vger.kernel.org> # v6.10+
> ---
>  drivers/gpu/drm/drm_atomic_state_helper.c     |  1 +
>  drivers/gpu/drm/drm_damage_helper.c           |  6 ++--
>  .../gpu/drm/tests/drm_damage_helper_test.c    | 28 +++++++++++++++++++
>  3 files changed, 31 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_atomic_state_helper.c b/drivers/gpu/drm/drm_atomic_state_helper.c
> index cc70508d4fdb..84d5231ccac1 100644
> --- a/drivers/gpu/drm/drm_atomic_state_helper.c
> +++ b/drivers/gpu/drm/drm_atomic_state_helper.c
> @@ -359,6 +359,7 @@ void __drm_atomic_helper_plane_duplicate_state(struct drm_plane *plane,
>  	state->fence = NULL;
>  	state->commit = NULL;
>  	state->fb_damage_clips = NULL;
> +	state->ignore_damage_clips = false;
>  	state->color_mgmt_changed = false;
>  }

I would split this as a separate patch since is the bug you are fixing for
commit 35ed38d58257 ("drm: Allow drivers to indicate the damage helpers to
ignore damage clips").

>  EXPORT_SYMBOL(__drm_atomic_helper_plane_duplicate_state);
> diff --git a/drivers/gpu/drm/drm_damage_helper.c b/drivers/gpu/drm/drm_damage_helper.c
> index 74a7f4252ecf..945fac8dc27b 100644
> --- a/drivers/gpu/drm/drm_damage_helper.c
> +++ b/drivers/gpu/drm/drm_damage_helper.c
> @@ -78,10 +78,8 @@ void drm_atomic_helper_check_plane_damage(struct drm_atomic_commit *state,
>  		if (WARN_ON(!crtc_state))
>  			return;
>  
> -		if (drm_atomic_crtc_needs_modeset(crtc_state)) {
> -			drm_property_blob_put(plane_state->fb_damage_clips);
> -			plane_state->fb_damage_clips = NULL;
> -		}
> +		if (drm_atomic_crtc_needs_modeset(crtc_state))
> +			plane_state->ignore_damage_clips = true;
>  	}
>  }

This makes sense to me as well and I agree that re-using the flag for this
is better than making plane_state->fb_damage_clips == NULL the condition.

As mentioned though, I would make it a separate patch. Both changes look
good to me:

Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>

-- 
Best regards,

Javier Martinez Canillas
Core Platforms
Red Hat