[v2 1/3] drm/edid: parse multiple CEA extension block

22 Feb 2022

Try to find and parse more CEA ext blocks if edid->extensions
is greater than one.
v2: add ext_index and look for available CEA block from
    ext_index in drm_find_cea_extension().
Cc: Jani Nikula jani.nikula@linux.intel.com
Cc: Ville Syrjala ville.syrjala@linux.intel.com
Cc: Ankit Nautiyal ankit.k.nautiyal@intel.com
Signed-off-by: Lee Shawn C shawn.c.lee@intel.com
---
 drivers/gpu/drm/drm_edid.c | 110 ++++++++++++++++++++-----------------
 1 file changed, 60 insertions(+), 50 deletions(-)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 12893e7be89b..c83ef23757bd 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -3353,16 +3353,14 @@ const u8 *drm_find_edid_extension(const struct edid *edid,
    return edid_ext;
 }
-static const u8 *drm_find_cea_extension(const struct edid *edid)
+static const u8 *drm_find_cea_extension(const struct edid *edid, int *ext_index)
 {
    const struct displayid_block *block;
    struct displayid_iter iter;
    const u8 *cea;
-	int ext_index = 0;
-	/* Look for a top level CEA extension block */
-	/* FIXME: make callers iterate through multiple CEA ext blocks? */
-	cea = drm_find_edid_extension(edid, CEA_EXT, &ext_index);
+	/* Look for a CEA extension block from ext_index */
+	cea = drm_find_edid_extension(edid, CEA_EXT, ext_index);
    if (cea)
    	return cea;
@@ -3643,10 +3641,10 @@ add_alternate_cea_modes(struct drm_connector *connector, struct edid *edid)
    struct drm_device *dev = connector->dev;
    struct drm_display_mode *mode, *tmp;
    LIST_HEAD(list);
-	int modes = 0;
+	int modes = 0, ext_index = 0;
/* Don't add CEA modes if the CEA extension block is missing */
-	if (!drm_find_cea_extension(edid))
+	if (!drm_find_cea_extension(edid, &ext_index))
    	return 0;
/*
@@ -4310,46 +4308,58 @@ static void drm_parse_y420cmdb_bitmap(struct drm_connector *connector,
 static int
 add_cea_modes(struct drm_connector *connector, struct edid *edid)
 {
-	const u8 *cea = drm_find_cea_extension(edid);
+	const u8 *cea = NULL;
    const u8 *db, *hdmi = NULL, *video = NULL;
    u8 dbl, hdmi_len, video_len = 0;
-	int modes = 0;
+	int modes = 0, j = 0;
-	if (cea && cea_revision(cea) >= 3) {
-		int i, start, end;
+	for (;;) {
+		cea = drm_find_cea_extension(edid, &j);
-		if (cea_db_offsets(cea, &start, &end))
-			return 0;
+		if (!cea)
+			break;
-		for_each_cea_db(cea, i, start, end) {
-			db = &cea[i];
-			dbl = cea_db_payload_len(db);
+		if (cea && cea_revision(cea) >= 3) {
+			int i, start, end;
+
+			if (cea_db_offsets(cea, &start, &end))
+				continue;
-			if (cea_db_tag(db) == VIDEO_BLOCK) {
-				video = db + 1;
-				video_len = dbl;
-				modes += do_cea_modes(connector, video, dbl);
-			} else if (cea_db_is_hdmi_vsdb(db)) {
-				hdmi = db;
-				hdmi_len = dbl;
-			} else if (cea_db_is_y420vdb(db)) {
-				const u8 *vdb420 = &db[2];
-
-				/* Add 4:2:0(only) modes present in EDID */
-				modes += do_y420vdb_modes(connector,
-							  vdb420,
-							  dbl - 1);
+			for_each_cea_db(cea, i, start, end) {
+				db = &cea[i];
+				dbl = cea_db_payload_len(db);
+
+				if (cea_db_tag(db) == VIDEO_BLOCK) {
+					video = db + 1;
+					video_len = dbl;
+					modes += do_cea_modes(connector, video, dbl);
+				} else if (cea_db_is_hdmi_vsdb(db)) {
+					hdmi = db;
+					hdmi_len = dbl;
+				} else if (cea_db_is_y420vdb(db)) {
+					const u8 *vdb420 = &db[2];
+
+					/* Add 4:2:0(only) modes present in EDID */
+					modes += do_y420vdb_modes(connector,
+								  vdb420,
+								  dbl - 1);
+				}
    		}
    	}
-	}
-	/*
-	 * We parse the HDMI VSDB after having added the cea modes as we will
-	 * be patching their flags when the sink supports stereo 3D.
-	 */
-	if (hdmi)
-		modes += do_hdmi_vsdb_modes(connector, hdmi, hdmi_len, video,
-					    video_len);
+		/*
+		 * We parse the HDMI VSDB after having added the cea modes as we will
+		 * be patching their flags when the sink supports stereo 3D.
+		 */
+		if (hdmi) {
+			modes += do_hdmi_vsdb_modes(connector, hdmi, hdmi_len, video,
+						    video_len);
+			hdmi  = NULL;
+			video = NULL;
+			hdmi_len = 0;
+			video_len = 0;
+		}
+	}
return modes;
 }
@@ -4551,7 +4561,7 @@ static void drm_edid_to_eld(struct drm_connector *connector, struct edid *edid)
    uint8_t *eld = connector->eld;
    const u8 *cea;
    const u8 *db;
-	int total_sad_count = 0;
+	int total_sad_count = 0, ext_index = 0;
    int mnl;
    int dbl;
@@ -4560,7 +4570,7 @@ static void drm_edid_to_eld(struct drm_connector *connector, struct edid *edid)
    if (!edid)
    	return;
-	cea = drm_find_cea_extension(edid);
+	cea = drm_find_cea_extension(edid, &ext_index);
    if (!cea) {
    	DRM_DEBUG_KMS("ELD: no CEA Extension found\n");
    	return;
@@ -4644,11 +4654,11 @@ static void drm_edid_to_eld(struct drm_connector *connector, struct edid *edid)
  */
 int drm_edid_to_sad(struct edid *edid, struct cea_sad **sads)
 {
-	int count = 0;
+	int count = 0, ext_index = 0;
    int i, start, end, dbl;
    const u8 *cea;
-	cea = drm_find_cea_extension(edid);
+	cea = drm_find_cea_extension(edid, &ext_index);
    if (!cea) {
    	DRM_DEBUG_KMS("SAD: no CEA Extension found\n");
    	return 0;
@@ -4706,11 +4716,11 @@ EXPORT_SYMBOL(drm_edid_to_sad);
  */
 int drm_edid_to_speaker_allocation(struct edid *edid, u8 **sadb)
 {
-	int count = 0;
+	int count = 0, ext_index = 0;
    int i, start, end, dbl;
    const u8 *cea;
-	cea = drm_find_cea_extension(edid);
+	cea = drm_find_cea_extension(edid, &ext_index);
    if (!cea) {
    	DRM_DEBUG_KMS("SAD: no CEA Extension found\n");
    	return 0;
@@ -4802,10 +4812,10 @@ EXPORT_SYMBOL(drm_av_sync_delay);
 bool drm_detect_hdmi_monitor(struct edid *edid)
 {
    const u8 *edid_ext;
-	int i;
+	int i, ext_index = 0;
    int start_offset, end_offset;
-	edid_ext = drm_find_cea_extension(edid);
+	edid_ext = drm_find_cea_extension(edid, &ext_index);
    if (!edid_ext)
    	return false;
@@ -4840,11 +4850,11 @@ EXPORT_SYMBOL(drm_detect_hdmi_monitor);
 bool drm_detect_monitor_audio(struct edid *edid)
 {
    const u8 *edid_ext;
-	int i, j;
+	int i, j, ext_index = 0;
    bool has_audio = false;
    int start_offset, end_offset;
-	edid_ext = drm_find_cea_extension(edid);
+	edid_ext = drm_find_cea_extension(edid, &ext_index);
    if (!edid_ext)
    	goto end;
@@ -5154,9 +5164,9 @@ static void drm_parse_cea_ext(struct drm_connector *connector,
 {
    struct drm_display_info *info = &connector->display_info;
    const u8 *edid_ext;
-	int i, start, end;
+	int i, start, end, ext_index = 0;
-	edid_ext = drm_find_cea_extension(edid);
+	edid_ext = drm_find_cea_extension(edid, &ext_index);
    if (!edid_ext)
    	return;
-- 
2.31.1


    

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[v2 1/3] drm/edid: parse multiple CEA extension block