From 40411f6d3ed6698387bcfb3aaeb1742e7a183e65 Mon Sep 17 00:00:00 2001
From: Simon Ser <contact@emersion.fr>
Date: Sat, 5 Dec 2020 14:36:47 +0100
Subject: [PATCH] Don't re-alloc when FB_DAMAGE_CLIPS changes

This is updated at each atomic commit.
---
 alloc.c             |  6 ++++--
 test/meson.build    |  1 +
 test/test_dynamic.c | 18 ++++++++++++++++++
 3 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/alloc.c b/alloc.c
index 2743b85..3d4a853 100644
--- a/alloc.c
+++ b/alloc.c
@@ -526,8 +526,10 @@ static bool layer_needs_realloc(struct liftoff_layer *layer)
 			continue;
 		}
 
-		/* We should never need a re-alloc when IN_FENCE_FD changes. */
-		if (strcmp(prop->name, "IN_FENCE_FD") == 0) {
+		/* We should never need a re-alloc when IN_FENCE_FD or
+		 * FB_DAMAGE_CLIPS changes. */
+		if (strcmp(prop->name, "IN_FENCE_FD") == 0 ||
+		    strcmp(prop->name, "FB_DAMAGE_CLIPS") == 0) {
 			continue;
 		}
 
diff --git a/test/meson.build b/test/meson.build
index a3e0553..9dfead7 100644
--- a/test/meson.build
+++ b/test/meson.build
@@ -60,6 +60,7 @@ tests = {
 		'unset-alpha-to-opaque',
 		'unset-alpha-to-transparent',
 		'change-in-fence-fd',
+		'change-fb-damage-clips',
 	],
 	'priority': [
 		#'basic',
diff --git a/test/test_dynamic.c b/test/test_dynamic.c
index 6e54053..15d74f0 100644
--- a/test/test_dynamic.c
+++ b/test/test_dynamic.c
@@ -228,6 +228,18 @@ static void run_change_in_fence_fd(struct context *ctx) {
 	assert(liftoff_mock_plane_get_layer(ctx->mock_plane) == ctx->layer);
 }
 
+static void run_change_fb_damage_clips(struct context *ctx) {
+	liftoff_layer_set_property(ctx->layer, "FB_DAMAGE_CLIPS", 42);
+
+	first_commit(ctx);
+	assert(liftoff_mock_plane_get_layer(ctx->mock_plane) == ctx->layer);
+
+	liftoff_layer_set_property(ctx->layer, "FB_DAMAGE_CLIPS", 43);
+
+	second_commit(ctx, true);
+	assert(liftoff_mock_plane_get_layer(ctx->mock_plane) == ctx->layer);
+}
+
 static const struct test_case tests[] = {
 	{ .name = "same", .run = run_same },
 	{ .name = "change-fb", .run = run_change_fb },
@@ -242,6 +254,7 @@ static const struct test_case tests[] = {
 	{ .name = "unset-alpha-to-opaque", .run = run_unset_alpha_to_opaque },
 	{ .name = "unset-alpha-to-transparent", .run = run_unset_alpha_to_transparent },
 	{ .name = "change-in-fence-fd", .run = run_change_in_fence_fd },
+	{ .name = "change-fb-damage-clips", .run = run_change_fb_damage_clips },
 };
 
 static void run(const struct test_case *test) {
@@ -269,6 +282,11 @@ static void run(const struct test_case *test) {
 	strncpy(prop.name, prop_name, sizeof(prop.name) - 1);
 	liftoff_mock_plane_add_property(ctx.mock_plane, &prop);
 
+	prop_name = "FB_DAMAGE_CLIPS";
+	prop = (drmModePropertyRes){0};
+	strncpy(prop.name, prop_name, sizeof(prop.name) - 1);
+	liftoff_mock_plane_add_property(ctx.mock_plane, &prop);
+
 	ctx.drm_fd = liftoff_mock_drm_open();
 	device = liftoff_device_create(ctx.drm_fd);
 	assert(device != NULL);