drm/selftest: Add drm damage helper selftest

Selftest for drm damage helper iterator functions.

v2: Rebase to new test-drm_modeset.

Signed-off-by: Deepak Rawat <drawat@vmware.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>

1 files changed, 811 insertions, 0 deletions

diff --git a/drivers/gpu/drm/selftests/test-drm_damage_helper.c b/drivers/gpu/drm/selftests/test-drm_damage_helper.c
new file mode 100644
index 000000000000..a2f753205a3e
--- /dev/null
+++ b/drivers/gpu/drm/selftests/test-drm_damage_helper.c
@@ -0,0 +1,811 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Test case for drm_damage_helper functions
+ */
+
+#define pr_fmt(fmt) "drm_damage_helper: " fmt
+
+#include <drm/drm_damage_helper.h>
+
+#include "test-drm_modeset_common.h"
+
+static void set_plane_src(struct drm_plane_state *state, int x1, int y1, int x2,
+			  int y2)
+{
+	state->src.x1 = x1;
+	state->src.y1 = y1;
+	state->src.x2 = x2;
+	state->src.y2 = y2;
+}
+
+static void set_damage_clip(struct drm_mode_rect *r, int x1, int y1, int x2,
+			    int y2)
+{
+	r->x1 = x1;
+	r->y1 = y1;
+	r->x2 = x2;
+	r->y2 = y2;
+}
+
+static void set_damage_blob(struct drm_property_blob *damage_blob,
+			    struct drm_mode_rect *r, uint32_t size)
+{
+	damage_blob->length = size;
+	damage_blob->data = r;
+}
+
+static void set_plane_damage(struct drm_plane_state *state,
+			     struct drm_property_blob *damage_blob)
+{
+	state->fb_damage_clips = damage_blob;
+}
+
+static bool check_damage_clip(struct drm_plane_state *state, struct drm_rect *r,
+			      int x1, int y1, int x2, int y2)
+{
+	/*
+	 * Round down x1/y1 and round up x2/y2. This is because damage is not in
+	 * 16.16 fixed point so to catch all pixels.
+	 */
+	int src_x1 = state->src.x1 >> 16;
+	int src_y1 = state->src.y1 >> 16;
+	int src_x2 = (state->src.x2 >> 16) + !!(state->src.x2 & 0xFFFF);
+	int src_y2 = (state->src.y2 >> 16) + !!(state->src.y2 & 0xFFFF);
+
+	if (x1 >= x2 || y1 >= y2) {
+		pr_err("Cannot have damage clip with no dimention.\n");
+		return false;
+	}
+
+	if (x1 < src_x1 || y1 < src_y1 || x2 > src_x2 || y2 > src_y2) {
+		pr_err("Damage cannot be outside rounded plane src.\n");
+		return false;
+	}
+
+	if (r->x1 != x1 || r->y1 != y1 || r->x2 != x2 || r->y2 != y2) {
+		pr_err("Damage = %d %d %d %d\n", r->x1, r->y1, r->x2, r->y2);
+		return false;
+	}
+
+	return true;
+}
+
+int igt_damage_iter_no_damage(void *ignored)
+{
+	struct drm_atomic_helper_damage_iter iter;
+	struct drm_plane_state old_state;
+	struct drm_rect clip;
+	uint32_t num_hits = 0;
+
+	struct drm_framebuffer fb = {
+		.width = 2048,
+		.height = 2048
+	};
+
+	struct drm_plane_state state = {
+		.crtc = ZERO_SIZE_PTR,
+		.fb = &fb,
+		.visible = true,
+	};
+
+	/* Plane src same as fb size. */
+	set_plane_src(&old_state, 0, 0, fb.width << 16, fb.height << 16);
+	set_plane_src(&state, 0, 0, fb.width << 16, fb.height << 16);
+	drm_atomic_helper_damage_iter_init(&iter, &old_state, &state);
+	drm_atomic_for_each_plane_damage(&iter, &clip)
+		num_hits++;
+
+	FAIL(num_hits != 1, "Should return plane src as damage.");
+	FAIL_ON(!check_damage_clip(&state, &clip, 0, 0, 2048, 2048));
+
+	return 0;
+}
+
+int igt_damage_iter_no_damage_fractional_src(void *ignored)
+{
+	struct drm_atomic_helper_damage_iter iter;
+	struct drm_plane_state old_state;
+	struct drm_rect clip;
+	uint32_t num_hits = 0;
+
+	struct drm_framebuffer fb = {
+		.width = 2048,
+		.height = 2048
+	};
+
+	struct drm_plane_state state = {
+		.crtc = ZERO_SIZE_PTR,
+		.fb = &fb,
+		.visible = true,
+	};
+
+	/* Plane src has fractional part. */
+	set_plane_src(&old_state, 0x3fffe, 0x3fffe,
+		      0x3fffe + (1024 << 16), 0x3fffe + (768 << 16));
+	set_plane_src(&state, 0x3fffe, 0x3fffe,
+		      0x3fffe + (1024 << 16), 0x3fffe + (768 << 16));
+	drm_atomic_helper_damage_iter_init(&iter, &old_state, &state);
+	drm_atomic_for_each_plane_damage(&iter, &clip)
+		num_hits++;
+
+	FAIL(num_hits != 1, "Should return rounded off plane src as damage.");
+	FAIL_ON(!check_damage_clip(&state, &clip, 3, 3, 1028, 772));
+
+	return 0;
+}
+
+int igt_damage_iter_no_damage_src_moved(void *ignored)
+{
+	struct drm_atomic_helper_damage_iter iter;
+	struct drm_plane_state old_state;
+	struct drm_rect clip;
+	uint32_t num_hits = 0;
+
+	struct drm_framebuffer fb = {
+		.width = 2048,
+		.height = 2048
+	};
+
+	struct drm_plane_state state = {
+		.crtc = ZERO_SIZE_PTR,
+		.fb = &fb,
+		.visible = true,
+	};
+
+	/* Plane src moved since old plane state. */
+	set_plane_src(&old_state, 0, 0, 1024 << 16, 768 << 16);
+	set_plane_src(&state, 10 << 16, 10 << 16,
+		      (10 + 1024) << 16, (10 + 768) << 16);
+	drm_atomic_helper_damage_iter_init(&iter, &old_state, &state);
+	drm_atomic_for_each_plane_damage(&iter, &clip)
+		num_hits++;
+
+	FAIL(num_hits != 1, "Should return plane src as damage.");
+	FAIL_ON(!check_damage_clip(&state, &clip, 10, 10, 1034, 778));
+
+	return 0;
+}
+
+int igt_damage_iter_no_damage_fractional_src_moved(void *ignored)
+{
+	struct drm_atomic_helper_damage_iter iter;
+	struct drm_plane_state old_state;
+	struct drm_rect clip;
+	uint32_t num_hits = 0;
+
+	struct drm_framebuffer fb = {
+		.width = 2048,
+		.height = 2048
+	};
+
+	struct drm_plane_state state = {
+		.crtc = ZERO_SIZE_PTR,
+		.fb = &fb,
+		.visible = true,
+	};
+
+	/* Plane src has fractional part and it moved since old plane state. */
+	set_plane_src(&old_state, 0x3fffe, 0x3fffe,
+		      0x3fffe + (1024 << 16), 0x3fffe + (768 << 16));
+	set_plane_src(&state, 0x40002, 0x40002,
+		      0x40002 + (1024 << 16), 0x40002 + (768 << 16));
+	drm_atomic_helper_damage_iter_init(&iter, &old_state, &state);
+	drm_atomic_for_each_plane_damage(&iter, &clip)
+		num_hits++;
+
+	FAIL(num_hits != 1, "Should return plane src as damage.");
+	FAIL_ON(!check_damage_clip(&state, &clip, 4, 4, 1029, 773));
+
+	return 0;
+}
+
+int igt_damage_iter_no_damage_not_visible(void *ignored)
+{
+	struct drm_atomic_helper_damage_iter iter;
+	struct drm_plane_state old_state;
+	struct drm_rect clip;
+	uint32_t num_hits = 0;
+
+	struct drm_framebuffer fb = {
+		.width = 2048,
+		.height = 2048
+	};
+
+	struct drm_plane_state state = {
+		.crtc = ZERO_SIZE_PTR,
+		.fb = &fb,
+		.visible = false,
+	};
+
+	set_plane_src(&old_state, 0, 0, 1024 << 16, 768 << 16);
+	set_plane_src(&state, 0, 0, 1024 << 16, 768 << 16);
+	drm_atomic_helper_damage_iter_init(&iter, &old_state, &state);
+	drm_atomic_for_each_plane_damage(&iter, &clip)
+		num_hits++;
+
+	FAIL(num_hits != 0, "Should have no damage.");
+
+	return 0;
+}
+
+int igt_damage_iter_no_damage_no_crtc(void *ignored)
+{
+	struct drm_atomic_helper_damage_iter iter;
+	struct drm_plane_state old_state;
+	struct drm_rect clip;
+	uint32_t num_hits = 0;
+
+	struct drm_framebuffer fb = {
+		.width = 2048,
+		.height = 2048
+	};
+
+	struct drm_plane_state state = {
+		.crtc = 0,
+		.fb = &fb,
+	};
+
+	set_plane_src(&old_state, 0, 0, 1024 << 16, 768 << 16);
+	set_plane_src(&state, 0, 0, 1024 << 16, 768 << 16);
+	drm_atomic_helper_damage_iter_init(&iter, &old_state, &state);
+	drm_atomic_for_each_plane_damage(&iter, &clip)
+		num_hits++;
+
+	FAIL(num_hits != 0, "Should have no damage.");
+
+	return 0;
+}
+
+int igt_damage_iter_no_damage_no_fb(void *ignored)
+{
+	struct drm_atomic_helper_damage_iter iter;
+	struct drm_plane_state old_state;
+	struct drm_rect clip;
+	uint32_t num_hits = 0;
+
+	struct drm_plane_state state = {
+		.crtc = ZERO_SIZE_PTR,
+		.fb = 0,
+	};
+
+	set_plane_src(&old_state, 0, 0, 1024 << 16, 768 << 16);
+	set_plane_src(&state, 0, 0, 1024 << 16, 768 << 16);
+	drm_atomic_helper_damage_iter_init(&iter, &old_state, &state);
+	drm_atomic_for_each_plane_damage(&iter, &clip)
+		num_hits++;
+
+	FAIL(num_hits != 0, "Should have no damage.");
+
+	return 0;
+}
+
+int igt_damage_iter_simple_damage(void *ignored)
+{
+	struct drm_atomic_helper_damage_iter iter;
+	struct drm_plane_state old_state;
+	struct drm_property_blob damage_blob;
+	struct drm_mode_rect damage;
+	struct drm_rect clip;
+	uint32_t num_hits = 0;
+
+	struct drm_framebuffer fb = {
+		.width = 2048,
+		.height = 2048
+	};
+
+	struct drm_plane_state state = {
+		.crtc = ZERO_SIZE_PTR,
+		.fb = &fb,
+		.visible = true,
+	};
+
+	set_plane_src(&old_state, 0, 0, 1024 << 16, 768 << 16);
+	set_plane_src(&state, 0, 0, 1024 << 16, 768 << 16);
+	/* Damage set to plane src */
+	set_damage_clip(&damage, 0, 0, 1024, 768);
+	set_damage_blob(&damage_blob, &damage, sizeof(damage));
+	set_plane_damage(&state, &damage_blob);
+	drm_atomic_helper_damage_iter_init(&iter, &old_state, &state);
+	drm_atomic_for_each_plane_damage(&iter, &clip)
+		num_hits++;
+
+	FAIL(num_hits != 1, "Should return damage when set.");
+	FAIL_ON(!check_damage_clip(&state, &clip, 0, 0, 1024, 768));
+
+	return 0;
+}
+
+int igt_damage_iter_single_damage(void *ignored)
+{
+	struct drm_atomic_helper_damage_iter iter;
+	struct drm_plane_state old_state;
+	struct drm_property_blob damage_blob;
+	struct drm_mode_rect damage;
+	struct drm_rect clip;
+	uint32_t num_hits = 0;
+
+	struct drm_framebuffer fb = {
+		.width = 2048,
+		.height = 2048
+	};
+
+	struct drm_plane_state state = {
+		.crtc = ZERO_SIZE_PTR,
+		.fb = &fb,
+		.visible = true,
+	};
+
+	set_plane_src(&old_state, 0, 0, 1024 << 16, 768 << 16);
+	set_plane_src(&state, 0, 0, 1024 << 16, 768 << 16);
+	set_damage_clip(&damage, 256, 192, 768, 576);
+	set_damage_blob(&damage_blob, &damage, sizeof(damage));
+	set_plane_damage(&state, &damage_blob);
+	drm_atomic_helper_damage_iter_init(&iter, &old_state, &state);
+	drm_atomic_for_each_plane_damage(&iter, &clip)
+		num_hits++;
+
+	FAIL(num_hits != 1, "Should return damage when set.");
+	FAIL_ON(!check_damage_clip(&state, &clip, 256, 192, 768, 576));
+
+	return 0;
+}
+
+int igt_damage_iter_single_damage_intersect_src(void *ignored)
+{
+	struct drm_atomic_helper_damage_iter iter;
+	struct drm_plane_state old_state;
+	struct drm_property_blob damage_blob;
+	struct drm_mode_rect damage;
+	struct drm_rect clip;
+	uint32_t num_hits = 0;
+
+	struct drm_framebuffer fb = {
+		.width = 2048,
+		.height = 2048
+	};
+
+	struct drm_plane_state state = {
+		.crtc = ZERO_SIZE_PTR,
+		.fb = &fb,
+		.visible = true,
+	};
+
+	set_plane_src(&old_state, 0, 0, 1024 << 16, 768 << 16);
+	set_plane_src(&state, 0, 0, 1024 << 16, 768 << 16);
+	/* Damage intersect with plane src. */
+	set_damage_clip(&damage, 256, 192, 1360, 768);
+	set_damage_blob(&damage_blob, &damage, sizeof(damage));
+	set_plane_damage(&state, &damage_blob);
+	drm_atomic_helper_damage_iter_init(&iter, &old_state, &state);
+	drm_atomic_for_each_plane_damage(&iter, &clip)
+		num_hits++;
+
+	FAIL(num_hits != 1, "Should return damage clipped to src.");
+	FAIL_ON(!check_damage_clip(&state, &clip, 256, 192, 1024, 768));
+
+	return 0;
+}
+
+int igt_damage_iter_single_damage_outside_src(void *ignored)
+{
+	struct drm_atomic_helper_damage_iter iter;
+	struct drm_plane_state old_state;
+	struct drm_property_blob damage_blob;
+	struct drm_mode_rect damage;
+	struct drm_rect clip;
+	uint32_t num_hits = 0;
+
+	struct drm_framebuffer fb = {
+		.width = 2048,
+		.height = 2048
+	};
+
+	struct drm_plane_state state = {
+		.crtc = ZERO_SIZE_PTR,
+		.fb = &fb,
+		.visible = true,
+	};
+
+	set_plane_src(&old_state, 0, 0, 1024 << 16, 768 << 16);
+	set_plane_src(&state, 0, 0, 1024 << 16, 768 << 16);
+	/* Damage clip outside plane src */
+	set_damage_clip(&damage, 1360, 1360, 1380, 1380);
+	set_damage_blob(&damage_blob, &damage, sizeof(damage));
+	set_plane_damage(&state, &damage_blob);
+	drm_atomic_helper_damage_iter_init(&iter, &old_state, &state);
+	drm_atomic_for_each_plane_damage(&iter, &clip)
+		num_hits++;
+
+	FAIL(num_hits != 0, "Should have no damage.");
+
+	return 0;
+}
+
+int igt_damage_iter_single_damage_fractional_src(void *ignored)
+{
+	struct drm_atomic_helper_damage_iter iter;
+	struct drm_plane_state old_state;
+	struct drm_property_blob damage_blob;
+	struct drm_mode_rect damage;
+	struct drm_rect clip;
+	uint32_t num_hits = 0;
+
+	struct drm_framebuffer fb = {
+		.width = 2048,
+		.height = 2048
+	};
+
+	struct drm_plane_state state = {
+		.crtc = ZERO_SIZE_PTR,
+		.fb = &fb,
+		.visible = true,
+	};
+
+	/* Plane src has fractional part. */
+	set_plane_src(&old_state, 0x40002, 0x40002,
+		      0x40002 + (1024 << 16), 0x40002 + (768 << 16));
+	set_plane_src(&state, 0x40002, 0x40002,
+		      0x40002 + (1024 << 16), 0x40002 + (768 << 16));
+	set_damage_clip(&damage, 10, 10, 256, 330);
+	set_damage_blob(&damage_blob, &damage, sizeof(damage));
+	set_plane_damage(&state, &damage_blob);
+	drm_atomic_helper_damage_iter_init(&iter, &old_state, &state);
+	drm_atomic_for_each_plane_damage(&iter, &clip)
+		num_hits++;
+
+	FAIL(num_hits != 1, "Should return damage when set.");
+	FAIL_ON(!check_damage_clip(&state, &clip, 10, 10, 256, 330));
+
+	return 0;
+}
+
+int igt_damage_iter_single_damage_intersect_fractional_src(void *ignored)
+{
+	struct drm_atomic_helper_damage_iter iter;
+	struct drm_plane_state old_state;
+	struct drm_property_blob damage_blob;
+	struct drm_mode_rect damage;
+	struct drm_rect clip;
+	uint32_t num_hits = 0;
+
+	struct drm_framebuffer fb = {
+		.width = 2048,
+		.height = 2048
+	};
+
+	struct drm_plane_state state = {
+		.crtc = ZERO_SIZE_PTR,
+		.fb = &fb,
+		.visible = true,
+	};
+
+	/* Plane src has fractional part. */
+	set_plane_src(&old_state, 0x40002, 0x40002,
+		      0x40002 + (1024 << 16), 0x40002 + (768 << 16));
+	set_plane_src(&state, 0x40002, 0x40002,
+		      0x40002 + (1024 << 16), 0x40002 + (768 << 16));
+	/* Damage intersect with plane src. */
+	set_damage_clip(&damage, 10, 1, 1360, 330);
+	set_damage_blob(&damage_blob, &damage, sizeof(damage));
+	set_plane_damage(&state, &damage_blob);
+	drm_atomic_helper_damage_iter_init(&iter, &old_state, &state);
+	drm_atomic_for_each_plane_damage(&iter, &clip)
+		num_hits++;
+
+	FAIL(num_hits != 1, "Should return damage clipped to rounded off src.");
+	FAIL_ON(!check_damage_clip(&state, &clip, 10, 4, 1029, 330));
+
+	return 0;
+}
+
+int igt_damage_iter_single_damage_outside_fractional_src(void *ignored)
+{
+	struct drm_atomic_helper_damage_iter iter;
+	struct drm_plane_state old_state;
+	struct drm_property_blob damage_blob;
+	struct drm_mode_rect damage;
+	struct drm_rect clip;
+	uint32_t num_hits = 0;
+
+	struct drm_framebuffer fb = {
+		.width = 2048,
+		.height = 2048
+	};
+
+	struct drm_plane_state state = {
+		.crtc = ZERO_SIZE_PTR,
+		.fb = &fb,
+		.visible = true,
+	};
+
+	/* Plane src has fractional part. */
+	set_plane_src(&old_state, 0x40002, 0x40002,
+		      0x40002 + (1024 << 16), 0x40002 + (768 << 16));
+	set_plane_src(&state, 0x40002, 0x40002,
+		      0x40002 + (1024 << 16), 0x40002 + (768 << 16));
+	/* Damage clip outside plane src */
+	set_damage_clip(&damage, 1360, 1360, 1380, 1380);
+	set_damage_blob(&damage_blob, &damage, sizeof(damage));
+	set_plane_damage(&state, &damage_blob);
+	drm_atomic_helper_damage_iter_init(&iter, &old_state, &state);
+	drm_atomic_for_each_plane_damage(&iter, &clip)
+		num_hits++;
+
+	FAIL(num_hits != 0, "Should have no damage.");
+
+	return 0;
+}
+
+int igt_damage_iter_single_damage_src_moved(void *ignored)
+{
+	struct drm_atomic_helper_damage_iter iter;
+	struct drm_plane_state old_state;
+	struct drm_property_blob damage_blob;
+	struct drm_mode_rect damage;
+	struct drm_rect clip;
+	uint32_t num_hits = 0;
+
+	struct drm_framebuffer fb = {
+		.width = 2048,
+		.height = 2048
+	};
+
+	struct drm_plane_state state = {
+		.crtc = ZERO_SIZE_PTR,
+		.fb = &fb,
+		.visible = true,
+	};
+
+	/* Plane src moved since old plane state. */
+	set_plane_src(&old_state, 0, 0, 1024 << 16, 768 << 16);
+	set_plane_src(&state, 10 << 16, 10 << 16,
+		      (10 + 1024) << 16, (10 + 768) << 16);
+	set_damage_clip(&damage, 20, 30, 256, 256);
+	set_damage_blob(&damage_blob, &damage, sizeof(damage));
+	set_plane_damage(&state, &damage_blob);
+	drm_atomic_helper_damage_iter_init(&iter, &old_state, &state);
+	drm_atomic_for_each_plane_damage(&iter, &clip)
+		num_hits++;
+
+	FAIL(num_hits != 1, "Should return plane src as damage.");
+	FAIL_ON(!check_damage_clip(&state, &clip, 10, 10, 1034, 778));
+
+	return 0;
+}
+
+int igt_damage_iter_single_damage_fractional_src_moved(void *ignored)
+{
+	struct drm_atomic_helper_damage_iter iter;
+	struct drm_plane_state old_state;
+	struct drm_property_blob damage_blob;
+	struct drm_mode_rect damage;
+	struct drm_rect clip;
+	uint32_t num_hits = 0;
+
+	struct drm_framebuffer fb = {
+		.width = 2048,
+		.height = 2048
+	};
+
+	struct drm_plane_state state = {
+		.crtc = ZERO_SIZE_PTR,
+		.fb = &fb,
+		.visible = true,
+	};
+
+	/* Plane src with fractional part moved since old plane state. */
+	set_plane_src(&old_state, 0x3fffe, 0x3fffe,
+		      0x3fffe + (1024 << 16), 0x3fffe + (768 << 16));
+	set_plane_src(&state, 0x40002, 0x40002,
+		      0x40002 + (1024 << 16), 0x40002 + (768 << 16));
+	/* Damage intersect with plane src. */
+	set_damage_clip(&damage, 20, 30, 1360, 256);
+	set_damage_blob(&damage_blob, &damage, sizeof(damage));
+	set_plane_damage(&state, &damage_blob);
+	drm_atomic_helper_damage_iter_init(&iter, &old_state, &state);
+	drm_atomic_for_each_plane_damage(&iter, &clip)
+		num_hits++;
+
+	FAIL(num_hits != 1, "Should return rounded off plane src as damage.");
+	FAIL_ON(!check_damage_clip(&state, &clip, 4, 4, 1029, 773));
+
+	return 0;
+}
+
+int igt_damage_iter_damage(void *ignored)
+{
+	struct drm_atomic_helper_damage_iter iter;
+	struct drm_plane_state old_state;
+	struct drm_property_blob damage_blob;
+	struct drm_mode_rect damage[2];
+	struct drm_rect clip;
+	uint32_t num_hits = 0;
+
+	struct drm_framebuffer fb = {
+		.width = 2048,
+		.height = 2048
+	};
+
+	struct drm_plane_state state = {
+		.crtc = ZERO_SIZE_PTR,
+		.fb = &fb,
+		.visible = true,
+	};
+
+	set_plane_src(&old_state, 0, 0, 1024 << 16, 768 << 16);
+	set_plane_src(&state, 0, 0, 1024 << 16, 768 << 16);
+	/* 2 damage clips. */
+	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(&state, &damage_blob);
+	drm_atomic_helper_damage_iter_init(&iter, &old_state, &state);
+	drm_atomic_for_each_plane_damage(&iter, &clip) {
+		if (num_hits == 0)
+			FAIL_ON(!check_damage_clip(&state, &clip, 20, 30, 200, 180));
+		if (num_hits == 1)
+			FAIL_ON(!check_damage_clip(&state, &clip, 240, 200, 280, 250));
+		num_hits++;
+	}
+
+	FAIL(num_hits != 2, "Should return damage when set.");
+
+	return 0;
+}
+
+int igt_damage_iter_damage_one_intersect(void *ignored)
+{
+	struct drm_atomic_helper_damage_iter iter;
+	struct drm_plane_state old_state;
+	struct drm_property_blob damage_blob;
+	struct drm_mode_rect damage[2];
+	struct drm_rect clip;
+	uint32_t num_hits = 0;
+
+	struct drm_framebuffer fb = {
+		.width = 2048,
+		.height = 2048
+	};
+
+	struct drm_plane_state state = {
+		.crtc = ZERO_SIZE_PTR,
+		.fb = &fb,
+		.visible = true,
+	};
+
+	set_plane_src(&old_state, 0x40002, 0x40002,
+		      0x40002 + (1024 << 16), 0x40002 + (768 << 16));
+	set_plane_src(&state, 0x40002, 0x40002,
+		      0x40002 + (1024 << 16), 0x40002 + (768 << 16));
+	/* 2 damage clips, one intersect plane src. */
+	set_damage_clip(&damage[0], 20, 30, 200, 180);
+	set_damage_clip(&damage[1], 2, 2, 1360, 1360);
+	set_damage_blob(&damage_blob, &damage[0], sizeof(damage));
+	set_plane_damage(&state, &damage_blob);
+	drm_atomic_helper_damage_iter_init(&iter, &old_state, &state);
+	drm_atomic_for_each_plane_damage(&iter, &clip) {
+		if (num_hits == 0)
+			FAIL_ON(!check_damage_clip(&state, &clip, 20, 30, 200, 180));
+		if (num_hits == 1)
+			FAIL_ON(!check_damage_clip(&state, &clip, 4, 4, 1029, 773));
+		num_hits++;
+	}
+
+	FAIL(num_hits != 2, "Should return damage when set.");
+
+	return 0;
+}
+
+int igt_damage_iter_damage_one_outside(void *ignored)
+{
+	struct drm_atomic_helper_damage_iter iter;
+	struct drm_plane_state old_state;
+	struct drm_property_blob damage_blob;
+	struct drm_mode_rect damage[2];
+	struct drm_rect clip;
+	uint32_t num_hits = 0;
+
+	struct drm_framebuffer fb = {
+		.width = 2048,
+		.height = 2048
+	};
+
+	struct drm_plane_state state = {
+		.crtc = ZERO_SIZE_PTR,
+		.fb = &fb,
+		.visible = true,
+	};
+
+	set_plane_src(&old_state, 0, 0, 1024 << 16, 768 << 16);
+	set_plane_src(&state, 0, 0, 1024 << 16, 768 << 16);
+	/* 2 damage clips, one outside plane src. */
+	set_damage_clip(&damage[0], 1360, 1360, 1380, 1380);
+	set_damage_clip(&damage[1], 240, 200, 280, 250);
+	set_damage_blob(&damage_blob, &damage[0], sizeof(damage));
+	set_plane_damage(&state, &damage_blob);
+	drm_atomic_helper_damage_iter_init(&iter, &old_state, &state);
+	drm_atomic_for_each_plane_damage(&iter, &clip)
+		num_hits++;
+
+	FAIL(num_hits != 1, "Should return damage when set.");
+	FAIL_ON(!check_damage_clip(&state, &clip, 240, 200, 280, 250));
+
+	return 0;
+}
+
+int igt_damage_iter_damage_src_moved(void *ignored)
+{
+	struct drm_atomic_helper_damage_iter iter;
+	struct drm_plane_state old_state;
+	struct drm_property_blob damage_blob;
+	struct drm_mode_rect damage[2];
+	struct drm_rect clip;
+	uint32_t num_hits = 0;
+
+	struct drm_framebuffer fb = {
+		.width = 2048,
+		.height = 2048
+	};
+
+	struct drm_plane_state state = {
+		.crtc = ZERO_SIZE_PTR,
+		.fb = &fb,
+		.visible = true,
+	};
+
+	set_plane_src(&old_state, 0x40002, 0x40002,
+		      0x40002 + (1024 << 16), 0x40002 + (768 << 16));
+	set_plane_src(&state, 0x3fffe, 0x3fffe,
+		      0x3fffe + (1024 << 16), 0x3fffe + (768 << 16));
+	/* 2 damage clips, one outside plane src. */
+	set_damage_clip(&damage[0], 1360, 1360, 1380, 1380);
+	set_damage_clip(&damage[1], 240, 200, 280, 250);
+	set_damage_blob(&damage_blob, &damage[0], sizeof(damage));
+	set_plane_damage(&state, &damage_blob);
+	drm_atomic_helper_damage_iter_init(&iter, &old_state, &state);
+	drm_atomic_for_each_plane_damage(&iter, &clip)
+		num_hits++;
+
+	FAIL(num_hits != 1, "Should return round off plane src as damage.");
+	FAIL_ON(!check_damage_clip(&state, &clip, 3, 3, 1028, 772));
+
+	return 0;
+}
+
+int igt_damage_iter_damage_not_visible(void *ignored)
+{
+	struct drm_atomic_helper_damage_iter iter;
+	struct drm_plane_state old_state;
+	struct drm_property_blob damage_blob;
+	struct drm_mode_rect damage[2];
+	struct drm_rect clip;
+	uint32_t num_hits = 0;
+
+	struct drm_framebuffer fb = {
+		.width = 2048,
+		.height = 2048
+	};
+
+	struct drm_plane_state state = {
+		.crtc = ZERO_SIZE_PTR,
+		.fb = &fb,
+		.visible = false,
+	};
+
+	set_plane_src(&old_state, 0x40002, 0x40002,
+		      0x40002 + (1024 << 16), 0x40002 + (768 << 16));
+	set_plane_src(&state, 0x3fffe, 0x3fffe,
+		      0x3fffe + (1024 << 16), 0x3fffe + (768 << 16));
+	/* 2 damage clips, one outside plane src. */
+	set_damage_clip(&damage[0], 1360, 1360, 1380, 1380);
+	set_damage_clip(&damage[1], 240, 200, 280, 250);
+	set_damage_blob(&damage_blob, &damage[0], sizeof(damage));
+	set_plane_damage(&state, &damage_blob);
+	drm_atomic_helper_damage_iter_init(&iter, &old_state, &state);
+	drm_atomic_for_each_plane_damage(&iter, &clip)
+		num_hits++;
+
+	FAIL(num_hits != 0, "Should not return any damage.");
+
+	return 0;
+}