Commit 37c90d58 authored by Thomas Zimmermann's avatar Thomas Zimmermann
Browse files

drm/fb-helper: Fix single-probe color-format selection 



Fix the color-format selection of the single-probe helper. Go
through all user-specified values and test each for compatibility
with the driver. If none is supported, use the driver-provided
default. This guarantees that the console is always available in
any color format at least.

Until now, the format selection of the single-probe helper tried
to either use a user-specified format or a 32-bit default format.
If the user-specified format was not supported by the driver, the
selection failed and the display remained blank.

Signed-off-by: default avatarThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: default avatarJavier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230102112927.26565-12-tzimmermann@suse.de
parent cff84bac

drivers/gpu/drm/drm_fb_helper.c

+94 −78
Original line number Diff line number Diff line
@@ -1726,109 +1726,125 @@ int drm_fb_helper_pan_display(struct fb_var_screeninfo *var, 
}

EXPORT_SYMBOL(drm_fb_helper_pan_display);





static int __drm_fb_helper_find_sizes(struct drm_fb_helper *fb_helper, int preferred_bpp,

				      struct drm_fb_helper_surface_size *sizes)

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;

	int crtc_count = 0;

	struct drm_connector_list_iter conn_iter;

	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);



	return DRM_FORMAT_INVALID;

}



static uint32_t drm_fb_helper_find_cmdline_format(struct drm_fb_helper *fb_helper,

						  const uint32_t *formats, size_t format_count,

						  const struct drm_cmdline_mode *cmdline_mode)

{

	struct drm_device *dev = fb_helper->dev;

	uint32_t bpp, depth;



	if (!cmdline_mode->bpp_specified)

		return DRM_FORMAT_INVALID;



		if (cmdline_mode->bpp_specified) {

	switch (cmdline_mode->bpp) {

	case 1:

	case 2:

	case 4:

	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;

		bpp = depth = cmdline_mode->bpp;

		break;

			case 32:

				sizes->surface_depth = 24;

				sizes->surface_bpp = 32;

	case 15:

		bpp = 16;

		depth = 15;

		break;

			}

	case 32:

		bpp = 32;

		depth = 24;

		break;

	default:

		drm_info(dev, "unsupported bpp value of %d\n", cmdline_mode->bpp);

		return DRM_FORMAT_INVALID;

	}



	return drm_fb_helper_find_format(fb_helper, formats, format_count, bpp, depth);

}

	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.

	 */

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;

		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;



			/* We found a perfect fit, great */

			if (fmt->depth == sizes->surface_depth) {

				best_depth = fmt->depth;

				break;

			surface_format = drm_fb_helper_find_cmdline_format(fb_helper,

									   plane->format_types,

									   plane->format_count,

									   cmdline_mode);

			if (surface_format != DRM_FORMAT_INVALID)

				break; /* found supported format */

		}

		drm_connector_list_iter_end(&conn_iter);



			/* Skip depths above what we're looking for */

			if (fmt->depth > sizes->surface_depth)

				continue;

		if (surface_format != DRM_FORMAT_INVALID)

			break; /* found supported format */



			/* Best depth found so far */

			if (fmt->depth > best_depth)

				best_depth = fmt->depth;

		/* try preferred bpp/depth */

		surface_format = drm_fb_helper_find_format(fb_helper, plane->format_types,

							   plane->format_count, preferred_bpp,

							   dev->mode_config.preferred_depth);

		if (surface_format != DRM_FORMAT_INVALID)

			break; /* found supported format */

	}



	if (surface_format == DRM_FORMAT_INVALID) {

		drm_warn(dev, "No compatible format found\n");

		return -EAGAIN;

	}

	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;

	}



	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;