compositor-drm: Dont pass ARGB format to addfb2 for primary fbs

Trying to create a ARGB framebuffer for scanout results in EINVAL when
trying to queue the pageflip.  This patch overrides the format we pass
to addfb2 in case of primary buffers like we do for sprites.

Since we always have to inspect and override the format, don't try to
look up the format in drm_fb_get_from_bo().  Instead return format from
drm_output_check_scanout_format().

Rename drm_surface_format_supported() to drm_output_check_sprite_format()
and make it follow the same convention.

We started scanning out ARGB surfaces in commit e920941032.

src/compositor-drm.c

@@ -213,11 +213,11 @@ drm_fb_destroy_callback(struct gbm_bo *bo, void *data)
 }
 
 static struct drm_fb *
-drm_fb_get_from_bo(struct gbm_bo *bo, struct drm_compositor *compositor,
-		   uint32_t override_format)
+drm_fb_get_from_bo(struct gbm_bo *bo,
+		   struct drm_compositor *compositor, uint32_t format)
 {
 	struct drm_fb *fb = gbm_bo_get_user_data(bo);
-	uint32_t width, height, stride, handle, format;
+	uint32_t width, height, stride, handle;
 	uint32_t handles[4], pitches[4], offsets[4];
 	int ret;
 
@@ -244,11 +244,6 @@ drm_fb_get_from_bo(struct gbm_bo *bo, struct drm_compositor *compositor,
 
 	ret = -1;
 
-	if (override_format)
-		format = override_format;
-	else
-		format = gbm_bo_get_format(bo);
-
 	if (format && !compositor->no_addfb2) {
 		handles[0] = handle;
 		pitches[0] = stride;
@@ -292,19 +287,19 @@ drm_fb_set_buffer(struct drm_fb *fb, struct wl_buffer *buffer)
 	weston_buffer_reference(&fb->buffer_ref, buffer);
 }
 
-static int
+static uint32_t
 drm_output_check_scanout_format(struct drm_output *output,
 				struct weston_surface *es, struct gbm_bo *bo)
 {
-	int ret = 0;
 	uint32_t format;
 	pixman_region32_t r;
 
 	format = gbm_bo_get_format(bo);
 
-	if (format == GBM_FORMAT_XRGB8888)
-		ret = 1;
-	else if (format == GBM_FORMAT_ARGB8888) {
+	switch (format) {
+	case GBM_FORMAT_XRGB8888:
+		return format;
+	case GBM_FORMAT_ARGB8888:
 		/* We can only scanout an ARGB buffer if the surface's
 		 * opaque region covers the whole output */
 		pixman_region32_init(&r);
@@ -312,12 +307,16 @@ drm_output_check_scanout_format(struct drm_output *output,
 					 &es->opaque);
 
 		if (!pixman_region32_not_empty(&r))
-			ret = 1;
+			format = GBM_FORMAT_XRGB8888;
+		else
+			format = 0;
 
 		pixman_region32_fini(&r);
-	}
 
-	return ret;
+		return format;
+	default:
+		return 0;
+	}
 }
 
 static struct weston_plane *
@@ -329,6 +328,7 @@ drm_output_prepare_scanout_surface(struct weston_output *_output,
 		(struct drm_compositor *) output->base.compositor;
 	struct wl_buffer *buffer = es->buffer_ref.buffer;
 	struct gbm_bo *bo;
+	uint32_t format;
 
 	if (es->geometry.x != output->base.x ||
 	    es->geometry.y != output->base.y ||
@@ -346,12 +346,13 @@ drm_output_prepare_scanout_surface(struct weston_output *_output,
 	if (!bo)
 		return NULL;
 
-	if (!drm_output_check_scanout_format(output, es, bo)) {
+	format = drm_output_check_scanout_format(output, es, bo);
+	if (format == 0) {
 		gbm_bo_destroy(bo);
 		return NULL;
 	}
 
-	output->next = drm_fb_get_from_bo(bo, c, 0);
+	output->next = drm_fb_get_from_bo(bo, c, format);
 	if (!output->next) {
 		gbm_bo_destroy(bo);
 		return NULL;
@@ -380,7 +381,7 @@ drm_output_render(struct drm_output *output, pixman_region32_t *damage)
 		return;
 	}
 
-	output->next = drm_fb_get_from_bo(bo, c, 0);
+	output->next = drm_fb_get_from_bo(bo, c, GBM_FORMAT_XRGB8888);
 	if (!output->next) {
 		weston_log("failed to get drm_fb for bo\n");
 		gbm_surface_release_buffer(output->surface, bo);
@@ -523,14 +524,30 @@ page_flip_handler(int fd, unsigned int frame,
 	}
 }
 
-static int
-drm_surface_format_supported(struct drm_sprite *s, uint32_t format)
+static uint32_t
+drm_output_check_sprite_format(struct drm_sprite *s,
+			       struct weston_surface *es, struct gbm_bo *bo)
 {
-	uint32_t i;
+	uint32_t i, format;
+
+	format = gbm_bo_get_format(bo);
+
+	if (format == GBM_FORMAT_ARGB8888) {
+		pixman_region32_t r;
+
+		pixman_region32_init(&r);
+		pixman_region32_subtract(&r, &es->transform.boundingbox,
+					 &es->transform.opaque);
+
+		if (!pixman_region32_not_empty(&r))
+			format = GBM_FORMAT_XRGB8888;
+
+		pixman_region32_fini(&r);
+	}
 
 	for (i = 0; i < s->count_formats; i++)
 		if (s->formats[i] == format)
-			return 1;
+			return format;
 
 	return 0;
 }
@@ -620,22 +637,8 @@ drm_output_prepare_overlay_surface(struct weston_output *output_base,
 	if (!bo)
 		return NULL;
 
-	format = gbm_bo_get_format(bo);
-
-	if (format == GBM_FORMAT_ARGB8888) {
-		pixman_region32_t r;
-
-		pixman_region32_init(&r);
-		pixman_region32_subtract(&r, &es->transform.boundingbox,
-					 &es->transform.opaque);
-
-		if (!pixman_region32_not_empty(&r))
-			format = GBM_FORMAT_XRGB8888;
-
-		pixman_region32_fini(&r);
-	}
-
-	if (!drm_surface_format_supported(s, format)) {
+	format = drm_output_check_sprite_format(s, es, bo);
+	if (format == 0) {
 		gbm_bo_destroy(bo);
 		return NULL;
 	}