Commit 8873cfa3 authored by Ville Syrjälä's avatar Ville Syrjälä
Browse files

drm/edid: Allow looking for ext blocks starting from a specified index 



Apparently EDIDs with multiple DispID ext blocks is a thing, so prepare
for iterating through multiple ext blocks of the same type by
passing the starting ext block index to drm_find_edid_extension(). Well
also have drm_find_edid_extension() update the index to point to the
next ext block on success. Thus we should be able to call
drm_find_edid_extension() in loop.

Signed-off-by: default avatarVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200527130310.27099-1-ville.syrjala@linux.intel.com


Reviewed-by: default avatarJosé Roberto de Souza <jose.souza@intel.com>
parent d4ad4eca

drivers/gpu/drm/drm_edid.c

+21 −9
Original line number Diff line number Diff line
@@ -3236,7 +3236,8 @@ add_detailed_modes(struct drm_connector *connector, struct edid *edid, 
/*

 * Search EDID for CEA extension block.

 */

static u8 *drm_find_edid_extension(const struct edid *edid, int ext_id)

static u8 *drm_find_edid_extension(const struct edid *edid,

				   int ext_id, int *ext_index)

{

	u8 *edid_ext = NULL;

	int i;
@@ -3246,23 +3247,26 @@ static u8 *drm_find_edid_extension(const struct edid *edid, int ext_id) 
		return NULL;



	/* Find CEA extension */

	for (i = 0; i < edid->extensions; i++) {

	for (i = *ext_index; i < edid->extensions; i++) {

		edid_ext = (u8 *)edid + EDID_LENGTH * (i + 1);

		if (edid_ext[0] == ext_id)

			break;

	}



	if (i == edid->extensions)

	if (i >= edid->extensions)

		return NULL;



	*ext_index = i + 1;



	return edid_ext;

}





static u8 *drm_find_displayid_extension(const struct edid *edid,

					int *length, int *idx)

					int *length, int *idx,

					int *ext_index)

{

	u8 *displayid = drm_find_edid_extension(edid, DISPLAYID_EXT);

	u8 *displayid = drm_find_edid_extension(edid, DISPLAYID_EXT, ext_index);

	struct displayid_hdr *base;

	int ret;
@@ -3289,14 +3293,18 @@ static u8 *drm_find_cea_extension(const struct edid *edid) 
	struct displayid_block *block;

	u8 *cea;

	u8 *displayid;

	int ext_index;



	/* Look for a top level CEA extension block */

	cea = drm_find_edid_extension(edid, CEA_EXT);

	ext_index = 0;

	cea = drm_find_edid_extension(edid, CEA_EXT, &ext_index);

	if (cea)

		return cea;



	/* CEA blocks can also be found embedded in a DisplayID block */

	displayid = drm_find_displayid_extension(edid, &length, &idx);

	ext_index = 0;

	displayid = drm_find_displayid_extension(edid, &length, &idx,

						 &ext_index);

	if (!displayid)

		return NULL;
@@ -5246,8 +5254,10 @@ static int add_displayid_detailed_modes(struct drm_connector *connector, 
	int length, idx;

	struct displayid_block *block;

	int num_modes = 0;

	int ext_index = 0;



	displayid = drm_find_displayid_extension(edid, &length, &idx);

	displayid = drm_find_displayid_extension(edid, &length, &idx,

						 &ext_index);

	if (!displayid)

		return 0;
@@ -5922,11 +5932,13 @@ void drm_update_tile_info(struct drm_connector *connector, 
			  const struct edid *edid)

{

	const void *displayid = NULL;

	int ext_index = 0;

	int length, idx;

	int ret;



	connector->has_tile = false;

	displayid = drm_find_displayid_extension(edid, &length, &idx);

	displayid = drm_find_displayid_extension(edid, &length, &idx,

						 &ext_index);

	if (!displayid) {

		/* drop reference to any tile group we had */

		goto out_drop_ref;