[PATCH v5 07/15] drm/damage-helper: Do not alter damage clips on modeset, but ignore them

[Thomas Zimmermann <tzimmermann@suse.de>]

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.

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.

v5:
- clear ignore_damage_clips in a separate patch (Javier)
v4:
- slightly reword the commit description

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Zack Rusin <zack.rusin@broadcom.com>
---
 drivers/gpu/drm/drm_damage_helper.c           |  6 ++--
 .../gpu/drm/tests/drm_damage_helper_test.c    | 28 +++++++++++++++++++
 2 files changed, 30 insertions(+), 4 deletions(-)

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