1 files changed, 154 insertions, 102 deletions

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index b3a731b9170a..427631706128 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -1726,117 +1726,132 @@ unlock:
 }
 EXPORT_SYMBOL(drm_fb_helper_pan_display);
 
-/*
- * Allocates the backing storage and sets up the fbdev info structure through
- * the ->fb_probe callback.
- */
-static int drm_fb_helper_single_fb_probe(struct drm_fb_helper *fb_helper,
-					 int preferred_bpp)
+static uint32_t drm_fb_helper_find_format(struct drm_fb_helper *fb_helper, const uint32_t *formats,
+					  size_t format_count, uint32_t bpp, uint32_t depth)
 {
-	struct drm_client_dev *client = &fb_helper->client;
 	struct drm_device *dev = fb_helper->dev;
-	struct drm_mode_config *config = &dev->mode_config;
-	int ret = 0;
-	int crtc_count = 0;
-	struct drm_connector_list_iter conn_iter;
-	struct drm_fb_helper_surface_size sizes;
-	struct drm_connector *connector;
-	struct drm_mode_set *mode_set;
-	int best_depth = 0;
-
-	memset(&sizes, 0, sizeof(struct drm_fb_helper_surface_size));
-	sizes.surface_depth = 24;
-	sizes.surface_bpp = 32;
-	sizes.fb_width = (u32)-1;
-	sizes.fb_height = (u32)-1;
+	uint32_t format;
+	size_t i;
 
 	/*
-	 * If driver picks 8 or 16 by default use that for both depth/bpp
-	 * to begin with
+	 * Do not consider YUV or other complicated formats
+	 * for framebuffers. This means only legacy formats
+	 * are supported (fmt->depth is a legacy field), but
+	 * the framebuffer emulation can only deal with such
+	 * formats, specifically RGB/BGA formats.
 	 */
-	if (preferred_bpp != sizes.surface_bpp)
-		sizes.surface_depth = sizes.surface_bpp = preferred_bpp;
+	format = drm_mode_legacy_fb_format(bpp, depth);
+	if (!format)
+		goto err;
 
-	drm_connector_list_iter_begin(fb_helper->dev, &conn_iter);
-	drm_client_for_each_connector_iter(connector, &conn_iter) {
-		struct drm_cmdline_mode *cmdline_mode;
+	for (i = 0; i < format_count; ++i) {
+		if (formats[i] == format)
+			return format;
+	}
 
-		cmdline_mode = &connector->cmdline_mode;
+err:
+	/* We found nothing. */
+	drm_warn(dev, "bpp/depth value of %u/%u not supported\n", bpp, depth);
 
-		if (cmdline_mode->bpp_specified) {
-			switch (cmdline_mode->bpp) {
-			case 8:
-				sizes.surface_depth = sizes.surface_bpp = 8;
-				break;
-			case 15:
-				sizes.surface_depth = 15;
-				sizes.surface_bpp = 16;
-				break;
-			case 16:
-				sizes.surface_depth = sizes.surface_bpp = 16;
-				break;
-			case 24:
-				sizes.surface_depth = sizes.surface_bpp = 24;
-				break;
-			case 32:
-				sizes.surface_depth = 24;
-				sizes.surface_bpp = 32;
-				break;
-			}
-			break;
-		}
+	return DRM_FORMAT_INVALID;
+}
+
+static uint32_t drm_fb_helper_find_color_mode_format(struct drm_fb_helper *fb_helper,
+						     const uint32_t *formats, size_t format_count,
+						     unsigned int color_mode)
+{
+	struct drm_device *dev = fb_helper->dev;
+	uint32_t bpp, depth;
+
+	switch (color_mode) {
+	case 1:
+	case 2:
+	case 4:
+	case 8:
+	case 16:
+	case 24:
+		bpp = depth = color_mode;
+		break;
+	case 15:
+		bpp = 16;
+		depth = 15;
+		break;
+	case 32:
+		bpp = 32;
+		depth = 24;
+		break;
+	default:
+		drm_info(dev, "unsupported color mode of %d\n", color_mode);
+		return DRM_FORMAT_INVALID;
 	}
-	drm_connector_list_iter_end(&conn_iter);
 
-	/*
-	 * If we run into a situation where, for example, the primary plane
-	 * supports RGBA5551 (16 bpp, depth 15) but not RGB565 (16 bpp, depth
-	 * 16) we need to scale down the depth of the sizes we request.
-	 */
-	mutex_lock(&client->modeset_mutex);
+	return drm_fb_helper_find_format(fb_helper, formats, format_count, bpp, depth);
+}
+
+static int __drm_fb_helper_find_sizes(struct drm_fb_helper *fb_helper, int preferred_bpp,
+				      struct drm_fb_helper_surface_size *sizes)
+{
+	struct drm_client_dev *client = &fb_helper->client;
+	struct drm_device *dev = fb_helper->dev;
+	int crtc_count = 0;
+	struct drm_connector_list_iter conn_iter;
+	struct drm_connector *connector;
+	struct drm_mode_set *mode_set;
+	uint32_t surface_format = DRM_FORMAT_INVALID;
+	const struct drm_format_info *info;
+
+	memset(sizes, 0, sizeof(*sizes));
+	sizes->fb_width = (u32)-1;
+	sizes->fb_height = (u32)-1;
+
 	drm_client_for_each_modeset(mode_set, client) {
 		struct drm_crtc *crtc = mode_set->crtc;
 		struct drm_plane *plane = crtc->primary;
-		int j;
 
 		drm_dbg_kms(dev, "test CRTC %u primary plane\n", drm_crtc_index(crtc));
 
-		for (j = 0; j < plane->format_count; j++) {
-			const struct drm_format_info *fmt;
-
-			fmt = drm_format_info(plane->format_types[j]);
-
-			/*
-			 * Do not consider YUV or other complicated formats
-			 * for framebuffers. This means only legacy formats
-			 * are supported (fmt->depth is a legacy field) but
-			 * the framebuffer emulation can only deal with such
-			 * formats, specifically RGB/BGA formats.
-			 */
-			if (fmt->depth == 0)
-				continue;
-
-			/* We found a perfect fit, great */
-			if (fmt->depth == sizes.surface_depth) {
-				best_depth = fmt->depth;
-				break;
-			}
+		drm_connector_list_iter_begin(fb_helper->dev, &conn_iter);
+		drm_client_for_each_connector_iter(connector, &conn_iter) {
+			struct drm_cmdline_mode *cmdline_mode = &connector->cmdline_mode;
 
-			/* Skip depths above what we're looking for */
-			if (fmt->depth > sizes.surface_depth)
+			if (!cmdline_mode->bpp_specified)
 				continue;
 
-			/* Best depth found so far */
-			if (fmt->depth > best_depth)
-				best_depth = fmt->depth;
+			surface_format = drm_fb_helper_find_color_mode_format(fb_helper,
+									      plane->format_types,
+									      plane->format_count,
+									      cmdline_mode->bpp);
+			if (surface_format != DRM_FORMAT_INVALID)
+				break; /* found supported format */
 		}
+		drm_connector_list_iter_end(&conn_iter);
+
+		if (surface_format != DRM_FORMAT_INVALID)
+			break; /* found supported format */
+
+		/* try preferred color mode */
+		surface_format = drm_fb_helper_find_color_mode_format(fb_helper,
+								      plane->format_types,
+								      plane->format_count,
+								      preferred_bpp);
+		if (surface_format != DRM_FORMAT_INVALID)
+			break; /* found supported format */
 	}
-	if (sizes.surface_depth != best_depth && best_depth) {
-		drm_info(dev, "requested bpp %d, scaled depth down to %d",
-			 sizes.surface_bpp, best_depth);
-		sizes.surface_depth = best_depth;
+
+	if (surface_format == DRM_FORMAT_INVALID) {
+		/*
+		 * If none of the given color modes works, fall back
+		 * to XRGB8888. Drivers are expected to provide this
+		 * format for compatibility with legacy applications.
+		 */
+		drm_warn(dev, "No compatible format found\n");
+		surface_format = drm_driver_legacy_fb_format(dev, 32, 24);
 	}
 
+	info = drm_format_info(surface_format);
+	sizes->surface_bpp = drm_format_info_bpp(info, 0);
+	sizes->surface_depth = info->depth;
+
 	/* first up get a count of crtcs now in use and new min/maxes width/heights */
 	crtc_count = 0;
 	drm_client_for_each_modeset(mode_set, client) {
@@ -1858,8 +1873,10 @@ static int drm_fb_helper_single_fb_probe(struct drm_fb_helper *fb_helper,
 		x = mode_set->x;
 		y = mode_set->y;
 
-		sizes.surface_width  = max_t(u32, desired_mode->hdisplay + x, sizes.surface_width);
-		sizes.surface_height = max_t(u32, desired_mode->vdisplay + y, sizes.surface_height);
+		sizes->surface_width  =
+			max_t(u32, desired_mode->hdisplay + x, sizes->surface_width);
+		sizes->surface_height =
+			max_t(u32, desired_mode->vdisplay + y, sizes->surface_height);
 
 		for (j = 0; j < mode_set->num_connectors; j++) {
 			struct drm_connector *connector = mode_set->connectors[j];
@@ -1875,28 +1892,63 @@ static int drm_fb_helper_single_fb_probe(struct drm_fb_helper *fb_helper,
 		}
 
 		if (lasth)
-			sizes.fb_width  = min_t(u32, desired_mode->hdisplay + x, sizes.fb_width);
+			sizes->fb_width  = min_t(u32, desired_mode->hdisplay + x, sizes->fb_width);
 		if (lastv)
-			sizes.fb_height = min_t(u32, desired_mode->vdisplay + y, sizes.fb_height);
+			sizes->fb_height = min_t(u32, desired_mode->vdisplay + y, sizes->fb_height);
 	}
-	mutex_unlock(&client->modeset_mutex);
 
-	if (crtc_count == 0 || sizes.fb_width == -1 || sizes.fb_height == -1) {
+	if (crtc_count == 0 || sizes->fb_width == -1 || sizes->fb_height == -1) {
 		drm_info(dev, "Cannot find any crtc or sizes\n");
-
-		/* First time: disable all crtc's.. */
-		if (!fb_helper->deferred_setup)
-			drm_client_modeset_commit(client);
 		return -EAGAIN;
 	}
 
+	return 0;
+}
+
+static int drm_fb_helper_find_sizes(struct drm_fb_helper *fb_helper, int preferred_bpp,
+				    struct drm_fb_helper_surface_size *sizes)
+{
+	struct drm_client_dev *client = &fb_helper->client;
+	struct drm_device *dev = fb_helper->dev;
+	struct drm_mode_config *config = &dev->mode_config;
+	int ret;
+
+	mutex_lock(&client->modeset_mutex);
+	ret = __drm_fb_helper_find_sizes(fb_helper, preferred_bpp, sizes);
+	mutex_unlock(&client->modeset_mutex);
+
+	if (ret)
+		return ret;
+
 	/* Handle our overallocation */
-	sizes.surface_height *= drm_fbdev_overalloc;
-	sizes.surface_height /= 100;
-	if (sizes.surface_height > config->max_height) {
+	sizes->surface_height *= drm_fbdev_overalloc;
+	sizes->surface_height /= 100;
+	if (sizes->surface_height > config->max_height) {
 		drm_dbg_kms(dev, "Fbdev over-allocation too large; clamping height to %d\n",
 			    config->max_height);
-		sizes.surface_height = config->max_height;
+		sizes->surface_height = config->max_height;
+	}
+
+	return 0;
+}
+
+/*
+ * Allocates the backing storage and sets up the fbdev info structure through
+ * the ->fb_probe callback.
+ */
+static int drm_fb_helper_single_fb_probe(struct drm_fb_helper *fb_helper,
+					 int preferred_bpp)
+{
+	struct drm_client_dev *client = &fb_helper->client;
+	struct drm_fb_helper_surface_size sizes;
+	int ret;
+
+	ret = drm_fb_helper_find_sizes(fb_helper, preferred_bpp, &sizes);
+	if (ret) {
+		/* First time: disable all crtc's.. */
+		if (!fb_helper->deferred_setup)
+			drm_client_modeset_commit(client);
+		return ret;
 	}
 
 #if IS_ENABLED(CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM)