[PATCH 00/19] drm/edid: CEA data block iterators, and more

[PATCH 00/19] drm/edid: CEA data block iterators, and more

[Jani Nikula]

Get back to the CEA data block iterator stuff now that a bunch of prep
work has landed.

My git repo at [1], branch edid-hfeeodb-2022-04-14, contains where this
is all headed after this.

[1] https://cgit.freedesktop.org/~jani/drm/log/?h=edid-hfeeodb-2022-04-14

Jani Nikula (18):
  drm/edid: reset display info in drm_add_edid_modes() for NULL edid
  drm/edid: clean up CTA data block tag definitions
  drm/edid: add iterator for EDID base and extension blocks
  drm/edid: add iterator for CTA data blocks
  drm/edid: clean up cea_db_is_*() functions
  drm/edid: convert add_cea_modes() to use cea db iter
  drm/edid: convert drm_edid_to_speaker_allocation() to use cea db iter
  drm/edid: convert drm_edid_to_sad() to use cea db iter
  drm/edid: convert drm_detect_hdmi_monitor() to use cea db iter
  drm/edid: convert drm_detect_monitor_audio() to use cea db iter
  drm/edid: convert drm_parse_cea_ext() to use cea db iter
  drm/edid: convert drm_edid_to_eld() to use cea db iter
  drm/edid: sunset the old unused cea data block iterators
  drm/edid: restore some type safety to cea_db_*() functions
  drm/edid: detect basic audio in all CEA extensions
  drm/edid: detect color formats and CTA revision in all CTA extensions
  drm/edid: skip CTA extension scan in drm_edid_to_eld() just for CTA
    rev
  drm/edid: sunset drm_find_cea_extension()

Lee Shawn C (1):
  drm/edid: check for HF-SCDB block

 drivers/gpu/drm/drm_edid.c | 760 +++++++++++++++++++++----------------
 1 file changed, 438 insertions(+), 322 deletions(-)

-- 
2.30.2

[PATCH 01/19] drm/edid: reset display info in drm_add_edid_modes() for NULL edid

[Jani Nikula]

If a NULL edid gets passed to drm_add_edid_modes(), we should probably
also reset the display info.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
 drivers/gpu/drm/drm_edid.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 324ce8467915..4758e78fad82 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -5721,6 +5721,7 @@ static int drm_edid_connector_update(struct drm_connector *connector,
 	u32 quirks;
 
 	if (edid == NULL) {
+		drm_reset_display_info(connector);
 		clear_eld(connector);
 		return 0;
 	}
-- 
2.30.2

[PATCH 02/19] drm/edid: check for HF-SCDB block

[Jani Nikula]

From: Lee Shawn C <shawn.c.lee@intel.com>

Find HF-SCDB information in CEA extensions block. And retrieve
Max_TMDS_Character_Rate that support by sink device.

v2: HF-SCDB and HF-VSDBS carry the same SCDS data. Reuse
    drm_parse_hdmi_forum_vsdb() to parse this packet.

Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
Cc: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Cc: intel-gfx <intel-gfx@lists.freedesktop.org>
Signed-off-by: Lee Shawn C <shawn.c.lee@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
 drivers/gpu/drm/drm_edid.c | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 4758e78fad82..32ece9607b94 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -3495,6 +3495,7 @@ add_detailed_modes(struct drm_connector *connector, const struct edid *edid,
 #define EXT_VIDEO_CAPABILITY_BLOCK 0x00
 #define EXT_VIDEO_DATA_BLOCK_420	0x0E
 #define EXT_VIDEO_CAP_BLOCK_Y420CMDB 0x0F
+#define EXT_VIDEO_HF_SCDB_DATA_BLOCK	0x79
 #define EDID_BASIC_AUDIO	(1 << 6)
 #define EDID_CEA_YCRCB444	(1 << 5)
 #define EDID_CEA_YCRCB422	(1 << 4)
@@ -4426,6 +4427,20 @@ static bool cea_db_is_vcdb(const u8 *db)
 	return true;
 }
 
+static bool cea_db_is_hdmi_forum_scdb(const u8 *db)
+{
+	if (cea_db_tag(db) != USE_EXTENDED_TAG)
+		return false;
+
+	if (cea_db_payload_len(db) < 7)
+		return false;
+
+	if (cea_db_extended_tag(db) != EXT_VIDEO_HF_SCDB_DATA_BLOCK)
+		return false;
+
+	return true;
+}
+
 static bool cea_db_is_y420cmdb(const u8 *db)
 {
 	if (cea_db_tag(db) != USE_EXTENDED_TAG)
@@ -5387,7 +5402,8 @@ static void drm_parse_cea_ext(struct drm_connector *connector,
 
 		if (cea_db_is_hdmi_vsdb(db))
 			drm_parse_hdmi_vsdb_video(connector, db);
-		if (cea_db_is_hdmi_forum_vsdb(db))
+		if (cea_db_is_hdmi_forum_vsdb(db) ||
+		    cea_db_is_hdmi_forum_scdb(db))
 			drm_parse_hdmi_forum_vsdb(connector, db);
 		if (cea_db_is_microsoft_vsdb(db))
 			drm_parse_microsoft_vsdb(connector, db);
-- 
2.30.2

[PATCH 03/19] drm/edid: clean up CTA data block tag definitions

[Jani Nikula]

Add prefixed names, group, sort, add references.

v2:
- Updated references to CTA-861-H
- s/CEA/CTA/ in data block macros

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
---
 drivers/gpu/drm/drm_edid.c | 65 ++++++++++++++++++++------------------
 1 file changed, 35 insertions(+), 30 deletions(-)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 32ece9607b94..18b0ff223885 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -3486,16 +3486,21 @@ add_detailed_modes(struct drm_connector *connector, const struct edid *edid,
 	return closure.modes;
 }
 
-#define AUDIO_BLOCK	0x01
-#define VIDEO_BLOCK     0x02
-#define VENDOR_BLOCK    0x03
-#define SPEAKER_BLOCK	0x04
-#define HDR_STATIC_METADATA_BLOCK	0x6
-#define USE_EXTENDED_TAG 0x07
-#define EXT_VIDEO_CAPABILITY_BLOCK 0x00
-#define EXT_VIDEO_DATA_BLOCK_420	0x0E
-#define EXT_VIDEO_CAP_BLOCK_Y420CMDB 0x0F
-#define EXT_VIDEO_HF_SCDB_DATA_BLOCK	0x79
+/* CTA-861-H Table 60 - CTA Tag Codes */
+#define CTA_DB_AUDIO			1
+#define CTA_DB_VIDEO			2
+#define CTA_DB_VENDOR			3
+#define CTA_DB_SPEAKER			4
+#define CTA_DB_EXTENDED_TAG		7
+
+/* CTA-861-H Table 62 - CTA Extended Tag Codes */
+#define CTA_EXT_DB_VIDEO_CAP		0
+#define CTA_EXT_DB_VENDOR		1
+#define CTA_EXT_DB_HDR_STATIC_METADATA	6
+#define CTA_EXT_DB_420_VIDEO_DATA	14
+#define CTA_EXT_DB_420_VIDEO_CAP_MAP	15
+#define CTA_EXT_DB_HF_SCDB		0x79
+
 #define EDID_BASIC_AUDIO	(1 << 6)
 #define EDID_CEA_YCRCB444	(1 << 5)
 #define EDID_CEA_YCRCB422	(1 << 4)
@@ -4382,7 +4387,7 @@ cea_db_offsets(const u8 *cea, int *start, int *end)
 
 static bool cea_db_is_hdmi_vsdb(const u8 *db)
 {
-	if (cea_db_tag(db) != VENDOR_BLOCK)
+	if (cea_db_tag(db) != CTA_DB_VENDOR)
 		return false;
 
 	if (cea_db_payload_len(db) < 5)
@@ -4393,7 +4398,7 @@ static bool cea_db_is_hdmi_vsdb(const u8 *db)
 
 static bool cea_db_is_hdmi_forum_vsdb(const u8 *db)
 {
-	if (cea_db_tag(db) != VENDOR_BLOCK)
+	if (cea_db_tag(db) != CTA_DB_VENDOR)
 		return false;
 
 	if (cea_db_payload_len(db) < 7)
@@ -4404,7 +4409,7 @@ static bool cea_db_is_hdmi_forum_vsdb(const u8 *db)
 
 static bool cea_db_is_microsoft_vsdb(const u8 *db)
 {
-	if (cea_db_tag(db) != VENDOR_BLOCK)
+	if (cea_db_tag(db) != CTA_DB_VENDOR)
 		return false;
 
 	if (cea_db_payload_len(db) != 21)
@@ -4415,13 +4420,13 @@ static bool cea_db_is_microsoft_vsdb(const u8 *db)
 
 static bool cea_db_is_vcdb(const u8 *db)
 {
-	if (cea_db_tag(db) != USE_EXTENDED_TAG)
+	if (cea_db_tag(db) != CTA_DB_EXTENDED_TAG)
 		return false;
 
 	if (cea_db_payload_len(db) != 2)
 		return false;
 
-	if (cea_db_extended_tag(db) != EXT_VIDEO_CAPABILITY_BLOCK)
+	if (cea_db_extended_tag(db) != CTA_EXT_DB_VIDEO_CAP)
 		return false;
 
 	return true;
@@ -4429,13 +4434,13 @@ static bool cea_db_is_vcdb(const u8 *db)
 
 static bool cea_db_is_hdmi_forum_scdb(const u8 *db)
 {
-	if (cea_db_tag(db) != USE_EXTENDED_TAG)
+	if (cea_db_tag(db) != CTA_DB_EXTENDED_TAG)
 		return false;
 
 	if (cea_db_payload_len(db) < 7)
 		return false;
 
-	if (cea_db_extended_tag(db) != EXT_VIDEO_HF_SCDB_DATA_BLOCK)
+	if (cea_db_extended_tag(db) != CTA_EXT_DB_HF_SCDB)
 		return false;
 
 	return true;
@@ -4443,13 +4448,13 @@ static bool cea_db_is_hdmi_forum_scdb(const u8 *db)
 
 static bool cea_db_is_y420cmdb(const u8 *db)
 {
-	if (cea_db_tag(db) != USE_EXTENDED_TAG)
+	if (cea_db_tag(db) != CTA_DB_EXTENDED_TAG)
 		return false;
 
 	if (!cea_db_payload_len(db))
 		return false;
 
-	if (cea_db_extended_tag(db) != EXT_VIDEO_CAP_BLOCK_Y420CMDB)
+	if (cea_db_extended_tag(db) != CTA_EXT_DB_420_VIDEO_CAP_MAP)
 		return false;
 
 	return true;
@@ -4457,13 +4462,13 @@ static bool cea_db_is_y420cmdb(const u8 *db)
 
 static bool cea_db_is_y420vdb(const u8 *db)
 {
-	if (cea_db_tag(db) != USE_EXTENDED_TAG)
+	if (cea_db_tag(db) != CTA_DB_EXTENDED_TAG)
 		return false;
 
 	if (!cea_db_payload_len(db))
 		return false;
 
-	if (cea_db_extended_tag(db) != EXT_VIDEO_DATA_BLOCK_420)
+	if (cea_db_extended_tag(db) != CTA_EXT_DB_420_VIDEO_DATA)
 		return false;
 
 	return true;
@@ -4530,7 +4535,7 @@ add_cea_modes(struct drm_connector *connector, const struct edid *edid)
 			db = &cea[i];
 			dbl = cea_db_payload_len(db);
 
-			if (cea_db_tag(db) == VIDEO_BLOCK) {
+			if (cea_db_tag(db) == CTA_DB_VIDEO) {
 				video = db + 1;
 				video_len = dbl;
 				modes += do_cea_modes(connector, video, dbl);
@@ -4604,10 +4609,10 @@ static void fixup_detailed_cea_mode_clock(struct drm_display_mode *mode)
 
 static bool cea_db_is_hdmi_hdr_metadata_block(const u8 *db)
 {
-	if (cea_db_tag(db) != USE_EXTENDED_TAG)
+	if (cea_db_tag(db) != CTA_DB_EXTENDED_TAG)
 		return false;
 
-	if (db[1] != HDR_STATIC_METADATA_BLOCK)
+	if (db[1] != CTA_EXT_DB_HDR_STATIC_METADATA)
 		return false;
 
 	if (cea_db_payload_len(db) < 3)
@@ -4801,7 +4806,7 @@ static void drm_edid_to_eld(struct drm_connector *connector,
 			dbl = cea_db_payload_len(db);
 
 			switch (cea_db_tag(db)) {
-			case AUDIO_BLOCK:
+			case CTA_DB_AUDIO:
 				/* Audio Data Block, contains SADs */
 				sad_count = min(dbl / 3, 15 - total_sad_count);
 				if (sad_count >= 1)
@@ -4809,12 +4814,12 @@ static void drm_edid_to_eld(struct drm_connector *connector,
 					       &db[1], sad_count * 3);
 				total_sad_count += sad_count;
 				break;
-			case SPEAKER_BLOCK:
+			case CTA_DB_SPEAKER:
 				/* Speaker Allocation Data Block */
 				if (dbl >= 1)
 					eld[DRM_ELD_SPEAKER] = db[1];
 				break;
-			case VENDOR_BLOCK:
+			case CTA_DB_VENDOR:
 				/* HDMI Vendor-Specific Data Block */
 				if (cea_db_is_hdmi_vsdb(db))
 					drm_parse_hdmi_vsdb_audio(connector, db);
@@ -4875,7 +4880,7 @@ int drm_edid_to_sad(const struct edid *edid, struct cea_sad **sads)
 	for_each_cea_db(cea, i, start, end) {
 		const u8 *db = &cea[i];
 
-		if (cea_db_tag(db) == AUDIO_BLOCK) {
+		if (cea_db_tag(db) == CTA_DB_AUDIO) {
 			int j;
 
 			dbl = cea_db_payload_len(db);
@@ -4937,7 +4942,7 @@ int drm_edid_to_speaker_allocation(const struct edid *edid, u8 **sadb)
 	for_each_cea_db(cea, i, start, end) {
 		const u8 *db = &cea[i];
 
-		if (cea_db_tag(db) == SPEAKER_BLOCK) {
+		if (cea_db_tag(db) == CTA_DB_SPEAKER) {
 			dbl = cea_db_payload_len(db);
 
 			/* Speaker Allocation Data Block */
@@ -5068,7 +5073,7 @@ bool drm_detect_monitor_audio(const struct edid *edid)
 		goto end;
 
 	for_each_cea_db(edid_ext, i, start_offset, end_offset) {
-		if (cea_db_tag(&edid_ext[i]) == AUDIO_BLOCK) {
+		if (cea_db_tag(&edid_ext[i]) == CTA_DB_AUDIO) {
 			has_audio = true;
 			for (j = 1; j < cea_db_payload_len(&edid_ext[i]) + 1; j += 3)
 				DRM_DEBUG_KMS("CEA audio format %d\n",
-- 
2.30.2

[PATCH 04/19] drm/edid: add iterator for EDID base and extension blocks

[Jani Nikula]

Add an iterator abstraction for going through all the EDID blocks.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
 drivers/gpu/drm/drm_edid.c | 48 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 48 insertions(+)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 18b0ff223885..40ffd7aba157 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -1600,6 +1600,54 @@ static const void *edid_extension_block_data(const struct edid *edid, int index)
 	return edid_block_data(edid, index + 1);
 }
 
+/*
+ * EDID base and extension block iterator.
+ *
+ * struct drm_edid_iter iter;
+ * const u8 *block;
+ *
+ * drm_edid_iter_begin(edid, &iter);
+ * drm_edid_iter_for_each(block, &iter) {
+ *         // do stuff with block
+ * }
+ * drm_edid_iter_end(&iter);
+ */
+struct drm_edid_iter {
+	const struct edid *edid;
+
+	/* Current block index. */
+	int index;
+};
+
+static void drm_edid_iter_begin(const struct edid *edid,
+				struct drm_edid_iter *iter)
+{
+	memset(iter, 0, sizeof(*iter));
+
+	iter->edid = edid;
+}
+
+static const void *__drm_edid_iter_next(struct drm_edid_iter *iter)
+{
+	const void *block = NULL;
+
+	if (!iter->edid)
+		return NULL;
+
+	if (iter->index < edid_block_count(iter->edid))
+		block = edid_block_data(iter->edid, iter->index++);
+
+	return block;
+}
+
+#define drm_edid_iter_for_each(__block, __iter)			\
+	while (((__block) = __drm_edid_iter_next(__iter)))
+
+static void drm_edid_iter_end(struct drm_edid_iter *iter)
+{
+	memset(iter, 0, sizeof(*iter));
+}
+
 static const u8 edid_header[] = {
 	0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00
 };
-- 
2.30.2

[PATCH 05/19] drm/edid: add iterator for CTA data blocks

[Jani Nikula]

Add an iterator for CTA Data Blocks across EDID CTA Extensions and
DisplayID CTA Data Blocks.

v2: Update references, note why we can trust displayid ranges (Ville)

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
 drivers/gpu/drm/drm_edid.c | 202 ++++++++++++++++++++++++++++++++++---
 1 file changed, 190 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 40ffd7aba157..43d9e04f8fb9 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -4360,24 +4360,12 @@ do_hdmi_vsdb_modes(struct drm_connector *connector, const u8 *db, u8 len,
 	return modes;
 }
 
-static int
-cea_db_payload_len(const u8 *db)
-{
-	return db[0] & 0x1f;
-}
-
 static int
 cea_db_extended_tag(const u8 *db)
 {
 	return db[1];
 }
 
-static int
-cea_db_tag(const u8 *db)
-{
-	return db[0] >> 5;
-}
-
 static int
 cea_revision(const u8 *cea)
 {
@@ -4433,6 +4421,196 @@ cea_db_offsets(const u8 *cea, int *start, int *end)
 	return 0;
 }
 
+/*
+ * CTA Data Block iterator.
+ *
+ * Iterate through all CTA Data Blocks in both EDID CTA Extensions and DisplayID
+ * CTA Data Blocks.
+ *
+ * struct cea_db *db:
+ * struct cea_db_iter iter;
+ *
+ * cea_db_iter_edid_begin(edid, &iter);
+ * cea_db_iter_for_each(db, &iter) {
+ *         // do stuff with db
+ * }
+ * cea_db_iter_end(&iter);
+ */
+struct cea_db_iter {
+	struct drm_edid_iter edid_iter;
+	struct displayid_iter displayid_iter;
+
+	/* Current Data Block Collection. */
+	const u8 *collection;
+
+	/* Current Data Block index in current collection. */
+	int index;
+
+	/* End index in current collection. */
+	int end;
+};
+
+/* CTA-861-H section 7.4 CTA Data BLock Collection */
+struct cea_db {
+	u8 tag_length;
+	u8 data[];
+} __packed;
+
+static int cea_db_tag(const void *_db)
+{
+	/* FIXME: Transition to passing struct cea_db * everywhere. */
+	const struct cea_db *db = _db;
+
+	return db->tag_length >> 5;
+}
+
+static int cea_db_payload_len(const void *_db)
+{
+	/* FIXME: Transition to passing struct cea_db * everywhere. */
+	const struct cea_db *db = _db;
+
+	return db->tag_length & 0x1f;
+}
+
+static const void *cea_db_data(const struct cea_db *db)
+{
+	return db->data;
+}
+
+static void cea_db_iter_edid_begin(const struct edid *edid, struct cea_db_iter *iter)
+{
+	memset(iter, 0, sizeof(*iter));
+
+	drm_edid_iter_begin(edid, &iter->edid_iter);
+	displayid_iter_edid_begin(edid, &iter->displayid_iter);
+}
+
+static const struct cea_db *
+__cea_db_iter_current_block(const struct cea_db_iter *iter)
+{
+	const struct cea_db *db;
+
+	if (!iter->collection)
+		return NULL;
+
+	db = (const struct cea_db *)&iter->collection[iter->index];
+
+	if (iter->index + sizeof(*db) <= iter->end &&
+	    iter->index + sizeof(*db) + cea_db_payload_len(db) <= iter->end)
+		return db;
+
+	return NULL;
+}
+
+/*
+ * References:
+ * - VESA E-EDID v1.4
+ * - CTA-861-H section 7.3.3 CTA Extension Version 3
+ */
+static const void *__cea_db_iter_edid_next(struct cea_db_iter *iter)
+{
+	const u8 *ext;
+
+	drm_edid_iter_for_each(ext, &iter->edid_iter) {
+		/* Only support CTA Extension revision 3+ */
+		if (ext[0] != CEA_EXT || cea_revision(ext) < 3)
+			continue;
+
+		iter->index = 4;
+		iter->end = ext[2];
+		if (iter->end == 0)
+			iter->end = 127;
+		if (iter->end < 4 || iter->end > 127)
+			continue;
+
+		return ext;
+	}
+
+	return NULL;
+}
+
+/*
+ * References:
+ * - DisplayID v1.3 Appendix C: CEA Data Block within a DisplayID Data Block
+ * - DisplayID v2.0 section 4.10 CTA DisplayID Data Block
+ *
+ * Note that the above do not specify any connection between DisplayID Data
+ * Block revision and CTA Extension versions.
+ */
+static const void *__cea_db_iter_displayid_next(struct cea_db_iter *iter)
+{
+	const struct displayid_block *block;
+
+	displayid_iter_for_each(block, &iter->displayid_iter) {
+		if (block->tag != DATA_BLOCK_CTA)
+			continue;
+
+		/*
+		 * The displayid iterator has already verified the block bounds
+		 * in displayid_iter_block().
+		 */
+		iter->index = sizeof(*block);
+		iter->end = iter->index + block->num_bytes;
+
+		return block;
+	}
+
+	return NULL;
+}
+
+static const struct cea_db *__cea_db_iter_next(struct cea_db_iter *iter)
+{
+	const struct cea_db *db;
+
+	if (iter->collection) {
+		/* Current collection should always be valid. */
+		db = __cea_db_iter_current_block(iter);
+		if (WARN_ON(!db)) {
+			iter->collection = NULL;
+			return NULL;
+		}
+
+		/* Next block in CTA Data Block Collection */
+		iter->index += sizeof(*db) + cea_db_payload_len(db);
+
+		db = __cea_db_iter_current_block(iter);
+		if (db)
+			return db;
+	}
+
+	for (;;) {
+		/*
+		 * Find the next CTA Data Block Collection. First iterate all
+		 * the EDID CTA Extensions, then all the DisplayID CTA blocks.
+		 *
+		 * Per DisplayID v1.3 Appendix B: DisplayID as an EDID
+		 * Extension, it's recommended that DisplayID extensions are
+		 * exposed after all of the CTA Extensions.
+		 */
+		iter->collection = __cea_db_iter_edid_next(iter);
+		if (!iter->collection)
+			iter->collection = __cea_db_iter_displayid_next(iter);
+
+		if (!iter->collection)
+			return NULL;
+
+		db = __cea_db_iter_current_block(iter);
+		if (db)
+			return db;
+	}
+}
+
+#define cea_db_iter_for_each(__db, __iter) \
+	while (((__db) = __cea_db_iter_next(__iter)))
+
+static void cea_db_iter_end(struct cea_db_iter *iter)
+{
+	displayid_iter_end(&iter->displayid_iter);
+	drm_edid_iter_end(&iter->edid_iter);
+
+	memset(iter, 0, sizeof(*iter));
+}
+
 static bool cea_db_is_hdmi_vsdb(const u8 *db)
 {
 	if (cea_db_tag(db) != CTA_DB_VENDOR)
-- 
2.30.2

[PATCH 06/19] drm/edid: clean up cea_db_is_*() functions

[Jani Nikula]

Abstract helpers for matching vendor data blocks and extended tags, and
use them to simplify all the cea_db_is_*() functions.

Take void pointer as parameter to allow transitional use for both u8 *
and struct cea_db *.

v2: Remove superfluous parens (Ville)

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
 drivers/gpu/drm/drm_edid.c | 127 ++++++++++++-------------------------
 1 file changed, 40 insertions(+), 87 deletions(-)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 43d9e04f8fb9..34897b1417a5 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -4360,12 +4360,6 @@ do_hdmi_vsdb_modes(struct drm_connector *connector, const u8 *db, u8 len,
 	return modes;
 }
 
-static int
-cea_db_extended_tag(const u8 *db)
-{
-	return db[1];
-}
-
 static int
 cea_revision(const u8 *cea)
 {
@@ -4477,6 +4471,22 @@ static const void *cea_db_data(const struct cea_db *db)
 	return db->data;
 }
 
+static bool cea_db_is_extended_tag(const struct cea_db *db, int tag)
+{
+	return cea_db_tag(db) == CTA_DB_EXTENDED_TAG &&
+		cea_db_payload_len(db) >= 1 &&
+		db->data[0] == tag;
+}
+
+static bool cea_db_is_vendor(const struct cea_db *db, int vendor_oui)
+{
+	const u8 *data = cea_db_data(db);
+
+	return cea_db_tag(db) == CTA_DB_VENDOR &&
+		cea_db_payload_len(db) >= 3 &&
+		oui(data[2], data[1], data[0]) == vendor_oui;
+}
+
 static void cea_db_iter_edid_begin(const struct edid *edid, struct cea_db_iter *iter)
 {
 	memset(iter, 0, sizeof(*iter));
@@ -4611,93 +4621,50 @@ static void cea_db_iter_end(struct cea_db_iter *iter)
 	memset(iter, 0, sizeof(*iter));
 }
 
-static bool cea_db_is_hdmi_vsdb(const u8 *db)
+static bool cea_db_is_hdmi_vsdb(const void *db)
 {
-	if (cea_db_tag(db) != CTA_DB_VENDOR)
-		return false;
-
-	if (cea_db_payload_len(db) < 5)
-		return false;
-
-	return oui(db[3], db[2], db[1]) == HDMI_IEEE_OUI;
+	return cea_db_is_vendor(db, HDMI_IEEE_OUI) &&
+		cea_db_payload_len(db) >= 5;
 }
 
-static bool cea_db_is_hdmi_forum_vsdb(const u8 *db)
+static bool cea_db_is_hdmi_forum_vsdb(const void *db)
 {
-	if (cea_db_tag(db) != CTA_DB_VENDOR)
-		return false;
-
-	if (cea_db_payload_len(db) < 7)
-		return false;
-
-	return oui(db[3], db[2], db[1]) == HDMI_FORUM_IEEE_OUI;
+	return cea_db_is_vendor(db, HDMI_FORUM_IEEE_OUI) &&
+		cea_db_payload_len(db) >= 7;
 }
 
-static bool cea_db_is_microsoft_vsdb(const u8 *db)
+static bool cea_db_is_microsoft_vsdb(const void *db)
 {
-	if (cea_db_tag(db) != CTA_DB_VENDOR)
-		return false;
-
-	if (cea_db_payload_len(db) != 21)
-		return false;
-
-	return oui(db[3], db[2], db[1]) == MICROSOFT_IEEE_OUI;
+	return cea_db_is_vendor(db, MICROSOFT_IEEE_OUI) &&
+		cea_db_payload_len(db) == 21;
 }
 
-static bool cea_db_is_vcdb(const u8 *db)
+static bool cea_db_is_vcdb(const void *db)
 {
-	if (cea_db_tag(db) != CTA_DB_EXTENDED_TAG)
-		return false;
-
-	if (cea_db_payload_len(db) != 2)
-		return false;
-
-	if (cea_db_extended_tag(db) != CTA_EXT_DB_VIDEO_CAP)
-		return false;
-
-	return true;
+	return cea_db_is_extended_tag(db, CTA_EXT_DB_VIDEO_CAP) &&
+		cea_db_payload_len(db) == 2;
 }
 
-static bool cea_db_is_hdmi_forum_scdb(const u8 *db)
+static bool cea_db_is_hdmi_forum_scdb(const void *db)
 {
-	if (cea_db_tag(db) != CTA_DB_EXTENDED_TAG)
-		return false;
-
-	if (cea_db_payload_len(db) < 7)
-		return false;
-
-	if (cea_db_extended_tag(db) != CTA_EXT_DB_HF_SCDB)
-		return false;
-
-	return true;
+	return cea_db_is_extended_tag(db, CTA_EXT_DB_HF_SCDB) &&
+		cea_db_payload_len(db) >= 7;
 }
 
-static bool cea_db_is_y420cmdb(const u8 *db)
+static bool cea_db_is_y420cmdb(const void *db)
 {
-	if (cea_db_tag(db) != CTA_DB_EXTENDED_TAG)
-		return false;
-
-	if (!cea_db_payload_len(db))
-		return false;
-
-	if (cea_db_extended_tag(db) != CTA_EXT_DB_420_VIDEO_CAP_MAP)
-		return false;
-
-	return true;
+	return cea_db_is_extended_tag(db, CTA_EXT_DB_420_VIDEO_CAP_MAP);
 }
 
-static bool cea_db_is_y420vdb(const u8 *db)
+static bool cea_db_is_y420vdb(const void *db)
 {
-	if (cea_db_tag(db) != CTA_DB_EXTENDED_TAG)
-		return false;
-
-	if (!cea_db_payload_len(db))
-		return false;
-
-	if (cea_db_extended_tag(db) != CTA_EXT_DB_420_VIDEO_DATA)
-		return false;
+	return cea_db_is_extended_tag(db, CTA_EXT_DB_420_VIDEO_DATA);
+}
 
-	return true;
+static bool cea_db_is_hdmi_hdr_metadata_block(const void *db)
+{
+	return cea_db_is_extended_tag(db, CTA_EXT_DB_HDR_STATIC_METADATA) &&
+		cea_db_payload_len(db) >= 3;
 }
 
 #define for_each_cea_db(cea, i, start, end) \
@@ -4833,20 +4800,6 @@ static void fixup_detailed_cea_mode_clock(struct drm_display_mode *mode)
 	mode->clock = clock;
 }
 
-static bool cea_db_is_hdmi_hdr_metadata_block(const u8 *db)
-{
-	if (cea_db_tag(db) != CTA_DB_EXTENDED_TAG)
-		return false;
-
-	if (db[1] != CTA_EXT_DB_HDR_STATIC_METADATA)
-		return false;
-
-	if (cea_db_payload_len(db) < 3)
-		return false;
-
-	return true;
-}
-
 static uint8_t eotf_supported(const u8 *edid_ext)
 {
 	return edid_ext[2] &
-- 
2.30.2

[PATCH 07/19] drm/edid: convert add_cea_modes() to use cea db iter

[Jani Nikula]

Iterate through all CTA EDID extension blocks and DisplayID CTA data
blocks to add CEA modes.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
 drivers/gpu/drm/drm_edid.c | 67 ++++++++++++++++++--------------------
 1 file changed, 31 insertions(+), 36 deletions(-)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 34897b1417a5..d02588637879 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -4713,46 +4713,41 @@ static void drm_parse_y420cmdb_bitmap(struct drm_connector *connector,
 static int
 add_cea_modes(struct drm_connector *connector, const struct edid *edid)
 {
-	const u8 *cea = drm_find_cea_extension(edid);
-	const u8 *db, *hdmi = NULL, *video = NULL;
-	u8 dbl, hdmi_len, video_len = 0;
+	const struct cea_db *db;
+	struct cea_db_iter iter;
 	int modes = 0;
 
-	if (cea && cea_revision(cea) >= 3) {
-		int i, start, end;
-
-		if (cea_db_offsets(cea, &start, &end))
-			return 0;
-
-		for_each_cea_db(cea, i, start, end) {
-			db = &cea[i];
-			dbl = cea_db_payload_len(db);
-
-			if (cea_db_tag(db) == CTA_DB_VIDEO) {
-				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);
-			}
+	cea_db_iter_edid_begin(edid, &iter);
+	cea_db_iter_for_each(db, &iter) {
+		const u8 *hdmi = NULL, *video = NULL;
+		u8 hdmi_len = 0, video_len = 0;
+
+		if (cea_db_tag(db) == CTA_DB_VIDEO) {
+			video = cea_db_data(db);
+			video_len = cea_db_payload_len(db);
+			modes += do_cea_modes(connector, video, video_len);
+		} else if (cea_db_is_hdmi_vsdb(db)) {
+			/* FIXME: Switch to use cea_db_data() */
+			hdmi = (const u8 *)db;
+			hdmi_len = cea_db_payload_len(db);
+		} else if (cea_db_is_y420vdb(db)) {
+			const u8 *vdb420 = cea_db_data(db) + 1;
+
+			/* Add 4:2:0(only) modes present in EDID */
+			modes += do_y420vdb_modes(connector, vdb420,
+						  cea_db_payload_len(db) - 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);
+	}
+	cea_db_iter_end(&iter);
 
 	return modes;
 }
-- 
2.30.2

[PATCH 08/19] drm/edid: convert drm_edid_to_speaker_allocation() to use cea db iter

[Jani Nikula]

Use the cea db iterator for speaker allocation. We'll still stop at the
first speaker data block, but not at the first CTA extension if that
doesn't have the info.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
 drivers/gpu/drm/drm_edid.c | 47 ++++++++++++--------------------------
 1 file changed, 15 insertions(+), 32 deletions(-)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index d02588637879..dac6a400905b 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -5093,42 +5093,25 @@ EXPORT_SYMBOL(drm_edid_to_sad);
  */
 int drm_edid_to_speaker_allocation(const struct edid *edid, u8 **sadb)
 {
+	const struct cea_db *db;
+	struct cea_db_iter iter;
 	int count = 0;
-	int i, start, end, dbl;
-	const u8 *cea;
 
-	cea = drm_find_cea_extension(edid);
-	if (!cea) {
-		DRM_DEBUG_KMS("SAD: no CEA Extension found\n");
-		return 0;
-	}
-
-	if (cea_revision(cea) < 3) {
-		DRM_DEBUG_KMS("SAD: wrong CEA revision\n");
-		return 0;
-	}
-
-	if (cea_db_offsets(cea, &start, &end)) {
-		DRM_DEBUG_KMS("SAD: invalid data block offsets\n");
-		return -EPROTO;
-	}
-
-	for_each_cea_db(cea, i, start, end) {
-		const u8 *db = &cea[i];
-
-		if (cea_db_tag(db) == CTA_DB_SPEAKER) {
-			dbl = cea_db_payload_len(db);
-
-			/* Speaker Allocation Data Block */
-			if (dbl == 3) {
-				*sadb = kmemdup(&db[1], dbl, GFP_KERNEL);
-				if (!*sadb)
-					return -ENOMEM;
-				count = dbl;
-				break;
-			}
+	cea_db_iter_edid_begin(edid, &iter);
+	cea_db_iter_for_each(db, &iter) {
+		if (cea_db_tag(db) == CTA_DB_SPEAKER &&
+		    cea_db_payload_len(db) == 3) {
+			*sadb = kmemdup(db->data, cea_db_payload_len(db),
+					GFP_KERNEL);
+			if (!*sadb)
+				return -ENOMEM;
+			count = cea_db_payload_len(db);
+			break;
 		}
 	}
+	cea_db_iter_end(&iter);
+
+	DRM_DEBUG_KMS("Found %d Speaker Allocation Data Blocks\n", count);
 
 	return count;
 }
-- 
2.30.2

[PATCH 09/19] drm/edid: convert drm_edid_to_sad() to use cea db iter

[Jani Nikula]

Use the cea db iterator for short audio descriptors. We'll still stop at
the first audio data block, but not at the first CTA Extension if that
doesn't have the info.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
 drivers/gpu/drm/drm_edid.c | 34 +++++++++-------------------------
 1 file changed, 9 insertions(+), 25 deletions(-)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index dac6a400905b..164a2020f9e1 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -5031,40 +5031,21 @@ static void drm_edid_to_eld(struct drm_connector *connector,
  */
 int drm_edid_to_sad(const struct edid *edid, struct cea_sad **sads)
 {
+	const struct cea_db *db;
+	struct cea_db_iter iter;
 	int count = 0;
-	int i, start, end, dbl;
-	const u8 *cea;
-
-	cea = drm_find_cea_extension(edid);
-	if (!cea) {
-		DRM_DEBUG_KMS("SAD: no CEA Extension found\n");
-		return 0;
-	}
-
-	if (cea_revision(cea) < 3) {
-		DRM_DEBUG_KMS("SAD: wrong CEA revision\n");
-		return 0;
-	}
-
-	if (cea_db_offsets(cea, &start, &end)) {
-		DRM_DEBUG_KMS("SAD: invalid data block offsets\n");
-		return -EPROTO;
-	}
-
-	for_each_cea_db(cea, i, start, end) {
-		const u8 *db = &cea[i];
 
+	cea_db_iter_edid_begin(edid, &iter);
+	cea_db_iter_for_each(db, &iter) {
 		if (cea_db_tag(db) == CTA_DB_AUDIO) {
 			int j;
 
-			dbl = cea_db_payload_len(db);
-
-			count = dbl / 3; /* SAD is 3B */
+			count = cea_db_payload_len(db) / 3; /* SAD is 3B */
 			*sads = kcalloc(count, sizeof(**sads), GFP_KERNEL);
 			if (!*sads)
 				return -ENOMEM;
 			for (j = 0; j < count; j++) {
-				const u8 *sad = &db[1 + j * 3];
+				const u8 *sad = &db->data[j * 3];
 
 				(*sads)[j].format = (sad[0] & 0x78) >> 3;
 				(*sads)[j].channels = sad[0] & 0x7;
@@ -5074,6 +5055,9 @@ int drm_edid_to_sad(const struct edid *edid, struct cea_sad **sads)
 			break;
 		}
 	}
+	cea_db_iter_end(&iter);
+
+	DRM_DEBUG_KMS("Found %d Short Audio Descriptors\n", count);
 
 	return count;
 }
-- 
2.30.2

[PATCH 10/19] drm/edid: convert drm_detect_hdmi_monitor() to use cea db iter

[Jani Nikula]

Iterate through all CTA data blocks, not just the first CTA extension.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
 drivers/gpu/drm/drm_edid.c | 25 +++++++++++--------------
 1 file changed, 11 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 164a2020f9e1..b1fac281fd85 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -5155,27 +5155,24 @@ EXPORT_SYMBOL(drm_av_sync_delay);
  */
 bool drm_detect_hdmi_monitor(const struct edid *edid)
 {
-	const u8 *edid_ext;
-	int i;
-	int start_offset, end_offset;
-
-	edid_ext = drm_find_cea_extension(edid);
-	if (!edid_ext)
-		return false;
-
-	if (cea_db_offsets(edid_ext, &start_offset, &end_offset))
-		return false;
+	const struct cea_db *db;
+	struct cea_db_iter iter;
+	bool hdmi = false;
 
 	/*
 	 * Because HDMI identifier is in Vendor Specific Block,
 	 * search it from all data blocks of CEA extension.
 	 */
-	for_each_cea_db(edid_ext, i, start_offset, end_offset) {
-		if (cea_db_is_hdmi_vsdb(&edid_ext[i]))
-			return true;
+	cea_db_iter_edid_begin(edid, &iter);
+	cea_db_iter_for_each(db, &iter) {
+		if (cea_db_is_hdmi_vsdb(db)) {
+			hdmi = true;
+			break;
+		}
 	}
+	cea_db_iter_end(&iter);
 
-	return false;
+	return hdmi;
 }
 EXPORT_SYMBOL(drm_detect_hdmi_monitor);
 
-- 
2.30.2

[PATCH 11/19] drm/edid: convert drm_detect_monitor_audio() to use cea db iter

[Jani Nikula]

Iterate through all CEA data blocks.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
 drivers/gpu/drm/drm_edid.c | 23 +++++++++++++----------
 1 file changed, 13 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index b1fac281fd85..e47bbcd103e6 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -5190,10 +5190,10 @@ EXPORT_SYMBOL(drm_detect_hdmi_monitor);
  */
 bool drm_detect_monitor_audio(const struct edid *edid)
 {
+	const struct cea_db *db;
+	struct cea_db_iter iter;
 	const u8 *edid_ext;
-	int i, j;
 	bool has_audio = false;
-	int start_offset, end_offset;
 
 	edid_ext = drm_find_cea_extension(edid);
 	if (!edid_ext)
@@ -5207,18 +5207,21 @@ bool drm_detect_monitor_audio(const struct edid *edid)
 		goto end;
 	}
 
-	if (cea_db_offsets(edid_ext, &start_offset, &end_offset))
-		goto end;
+	cea_db_iter_edid_begin(edid, &iter);
+	cea_db_iter_for_each(db, &iter) {
+		if (cea_db_tag(db) == CTA_DB_AUDIO) {
+			const u8 *data = cea_db_data(db);
+			int i;
 
-	for_each_cea_db(edid_ext, i, start_offset, end_offset) {
-		if (cea_db_tag(&edid_ext[i]) == CTA_DB_AUDIO) {
-			has_audio = true;
-			for (j = 1; j < cea_db_payload_len(&edid_ext[i]) + 1; j += 3)
+			for (i = 0; i < cea_db_payload_len(db); i += 3)
 				DRM_DEBUG_KMS("CEA audio format %d\n",
-					      (edid_ext[i + j] >> 3) & 0xf);
-			goto end;
+					      (data[i] >> 3) & 0xf);
+			has_audio = true;
+			break;
 		}
 	}
+	cea_db_iter_end(&iter);
+
 end:
 	return has_audio;
 }
-- 
2.30.2

[PATCH 12/19] drm/edid: convert drm_parse_cea_ext() to use cea db iter

[Jani Nikula]

Iterate through all CTA data blocks across all CTA Extensions and
DisplayID data blocks.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
 drivers/gpu/drm/drm_edid.c | 25 +++++++++++++------------
 1 file changed, 13 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index e47bbcd103e6..91f15b561d78 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -5520,8 +5520,9 @@ static void drm_parse_cea_ext(struct drm_connector *connector,
 			      const struct edid *edid)
 {
 	struct drm_display_info *info = &connector->display_info;
+	const struct cea_db *db;
+	struct cea_db_iter iter;
 	const u8 *edid_ext;
-	int i, start, end;
 
 	edid_ext = drm_find_cea_extension(edid);
 	if (!edid_ext)
@@ -5540,26 +5541,26 @@ static void drm_parse_cea_ext(struct drm_connector *connector,
 			info->color_formats |= DRM_COLOR_FORMAT_YCBCR422;
 	}
 
-	if (cea_db_offsets(edid_ext, &start, &end))
-		return;
-
-	for_each_cea_db(edid_ext, i, start, end) {
-		const u8 *db = &edid_ext[i];
+	cea_db_iter_edid_begin(edid, &iter);
+	cea_db_iter_for_each(db, &iter) {
+		/* FIXME: convert parsers to use struct cea_db */
+		const u8 *data = (const u8 *)db;
 
 		if (cea_db_is_hdmi_vsdb(db))
-			drm_parse_hdmi_vsdb_video(connector, db);
+			drm_parse_hdmi_vsdb_video(connector, data);
 		if (cea_db_is_hdmi_forum_vsdb(db) ||
 		    cea_db_is_hdmi_forum_scdb(db))
-			drm_parse_hdmi_forum_vsdb(connector, db);
+			drm_parse_hdmi_forum_vsdb(connector, data);
 		if (cea_db_is_microsoft_vsdb(db))
-			drm_parse_microsoft_vsdb(connector, db);
+			drm_parse_microsoft_vsdb(connector, data);
 		if (cea_db_is_y420cmdb(db))
-			drm_parse_y420cmdb_bitmap(connector, db);
+			drm_parse_y420cmdb_bitmap(connector, data);
 		if (cea_db_is_vcdb(db))
-			drm_parse_vcdb(connector, db);
+			drm_parse_vcdb(connector, data);
 		if (cea_db_is_hdmi_hdr_metadata_block(db))
-			drm_parse_hdr_metadata_block(connector, db);
+			drm_parse_hdr_metadata_block(connector, data);
 	}
+	cea_db_iter_end(&iter);
 }
 
 static
-- 
2.30.2

[PATCH 13/19] drm/edid: convert drm_edid_to_eld() to use cea db iter

[Jani Nikula]

Iterate through all CTA data blocks across all CTA extensions and
DisplayID data blocks. This may gather more data than before, and if
there's duplicated data, some is overwritten by whichever comes last.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
 drivers/gpu/drm/drm_edid.c | 64 +++++++++++++++++---------------------
 1 file changed, 29 insertions(+), 35 deletions(-)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 91f15b561d78..fa7f2bf68da3 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -4935,12 +4935,12 @@ static void clear_eld(struct drm_connector *connector)
 static void drm_edid_to_eld(struct drm_connector *connector,
 			    const struct edid *edid)
 {
+	const struct cea_db *db;
+	struct cea_db_iter iter;
 	uint8_t *eld = connector->eld;
 	const u8 *cea;
-	const u8 *db;
 	int total_sad_count = 0;
 	int mnl;
-	int dbl;
 
 	clear_eld(connector);
 
@@ -4966,43 +4966,37 @@ static void drm_edid_to_eld(struct drm_connector *connector,
 	eld[DRM_ELD_PRODUCT_CODE0] = edid->prod_code[0];
 	eld[DRM_ELD_PRODUCT_CODE1] = edid->prod_code[1];
 
-	if (cea_revision(cea) >= 3) {
-		int i, start, end;
+	cea_db_iter_edid_begin(edid, &iter);
+	cea_db_iter_for_each(db, &iter) {
+		const u8 *data = cea_db_data(db);
+		int len = cea_db_payload_len(db);
 		int sad_count;
 
-		if (cea_db_offsets(cea, &start, &end)) {
-			start = 0;
-			end = 0;
-		}
-
-		for_each_cea_db(cea, i, start, end) {
-			db = &cea[i];
-			dbl = cea_db_payload_len(db);
-
-			switch (cea_db_tag(db)) {
-			case CTA_DB_AUDIO:
-				/* Audio Data Block, contains SADs */
-				sad_count = min(dbl / 3, 15 - total_sad_count);
-				if (sad_count >= 1)
-					memcpy(&eld[DRM_ELD_CEA_SAD(mnl, total_sad_count)],
-					       &db[1], sad_count * 3);
-				total_sad_count += sad_count;
-				break;
-			case CTA_DB_SPEAKER:
-				/* Speaker Allocation Data Block */
-				if (dbl >= 1)
-					eld[DRM_ELD_SPEAKER] = db[1];
-				break;
-			case CTA_DB_VENDOR:
-				/* HDMI Vendor-Specific Data Block */
-				if (cea_db_is_hdmi_vsdb(db))
-					drm_parse_hdmi_vsdb_audio(connector, db);
-				break;
-			default:
-				break;
-			}
+		switch (cea_db_tag(db)) {
+		case CTA_DB_AUDIO:
+			/* Audio Data Block, contains SADs */
+			sad_count = min(len / 3, 15 - total_sad_count);
+			if (sad_count >= 1)
+				memcpy(&eld[DRM_ELD_CEA_SAD(mnl, total_sad_count)],
+				       data, sad_count * 3);
+			total_sad_count += sad_count;
+			break;
+		case CTA_DB_SPEAKER:
+			/* Speaker Allocation Data Block */
+			if (len >= 1)
+				eld[DRM_ELD_SPEAKER] = data[0];
+			break;
+		case CTA_DB_VENDOR:
+			/* HDMI Vendor-Specific Data Block */
+			if (cea_db_is_hdmi_vsdb(db))
+				drm_parse_hdmi_vsdb_audio(connector, (const u8 *)db);
+			break;
+		default:
+			break;
 		}
 	}
+	cea_db_iter_end(&iter);
+
 	eld[DRM_ELD_SAD_COUNT_CONN_TYPE] |= total_sad_count << DRM_ELD_SAD_COUNT_SHIFT;
 
 	if (connector->connector_type == DRM_MODE_CONNECTOR_DisplayPort ||
-- 
2.30.2

[PATCH 14/19] drm/edid: sunset the old unused cea data block iterators

[Jani Nikula]

All CTA data block iteration has now been converted to the new cea db
iterators.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
 drivers/gpu/drm/drm_edid.c | 45 --------------------------------------
 1 file changed, 45 deletions(-)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index fa7f2bf68da3..7ed0258c0edf 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -4373,48 +4373,6 @@ cea_revision(const u8 *cea)
 	return cea[1];
 }
 
-static int
-cea_db_offsets(const u8 *cea, int *start, int *end)
-{
-	/* DisplayID CTA extension blocks and top-level CEA EDID
-	 * block header definitions differ in the following bytes:
-	 *   1) Byte 2 of the header specifies length differently,
-	 *   2) Byte 3 is only present in the CEA top level block.
-	 *
-	 * The different definitions for byte 2 follow.
-	 *
-	 * DisplayID CTA extension block defines byte 2 as:
-	 *   Number of payload bytes
-	 *
-	 * CEA EDID block defines byte 2 as:
-	 *   Byte number (decimal) within this block where the 18-byte
-	 *   DTDs begin. If no non-DTD data is present in this extension
-	 *   block, the value should be set to 04h (the byte after next).
-	 *   If set to 00h, there are no DTDs present in this block and
-	 *   no non-DTD data.
-	 */
-	if (cea[0] == DATA_BLOCK_CTA) {
-		/*
-		 * for_each_displayid_db() has already verified
-		 * that these stay within expected bounds.
-		 */
-		*start = 3;
-		*end = *start + cea[2];
-	} else if (cea[0] == CEA_EXT) {
-		/* Data block offset in CEA extension block */
-		*start = 4;
-		*end = cea[2];
-		if (*end == 0)
-			*end = 127;
-		if (*end < 4 || *end > 127)
-			return -ERANGE;
-	} else {
-		return -EOPNOTSUPP;
-	}
-
-	return 0;
-}
-
 /*
  * CTA Data Block iterator.
  *
@@ -4667,9 +4625,6 @@ static bool cea_db_is_hdmi_hdr_metadata_block(const void *db)
 		cea_db_payload_len(db) >= 3;
 }
 
-#define for_each_cea_db(cea, i, start, end) \
-	for ((i) = (start); (i) < (end) && (i) + cea_db_payload_len(&(cea)[(i)]) < (end); (i) += cea_db_payload_len(&(cea)[(i)]) + 1)
-
 static void drm_parse_y420cmdb_bitmap(struct drm_connector *connector,
 				      const u8 *db)
 {
-- 
2.30.2

[PATCH 15/19] drm/edid: restore some type safety to cea_db_*() functions

[Jani Nikula]

During the transition, we accepted a void pointer for a poor C
programmer's version of polymorphism. Switch the functions to use struct
cea_db * to regain some more type safety.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
 drivers/gpu/drm/drm_edid.c | 21 +++++++++------------
 1 file changed, 9 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 7ed0258c0edf..1fc4e8754cd4 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -4408,11 +4408,8 @@ struct cea_db {
 	u8 data[];
 } __packed;
 
-static int cea_db_tag(const void *_db)
+static int cea_db_tag(const struct cea_db *db)
 {
-	/* FIXME: Transition to passing struct cea_db * everywhere. */
-	const struct cea_db *db = _db;
-
 	return db->tag_length >> 5;
 }
 
@@ -4579,47 +4576,47 @@ static void cea_db_iter_end(struct cea_db_iter *iter)
 	memset(iter, 0, sizeof(*iter));
 }
 
-static bool cea_db_is_hdmi_vsdb(const void *db)
+static bool cea_db_is_hdmi_vsdb(const struct cea_db *db)
 {
 	return cea_db_is_vendor(db, HDMI_IEEE_OUI) &&
 		cea_db_payload_len(db) >= 5;
 }
 
-static bool cea_db_is_hdmi_forum_vsdb(const void *db)
+static bool cea_db_is_hdmi_forum_vsdb(const struct cea_db *db)
 {
 	return cea_db_is_vendor(db, HDMI_FORUM_IEEE_OUI) &&
 		cea_db_payload_len(db) >= 7;
 }
 
-static bool cea_db_is_microsoft_vsdb(const void *db)
+static bool cea_db_is_microsoft_vsdb(const struct cea_db *db)
 {
 	return cea_db_is_vendor(db, MICROSOFT_IEEE_OUI) &&
 		cea_db_payload_len(db) == 21;
 }
 
-static bool cea_db_is_vcdb(const void *db)
+static bool cea_db_is_vcdb(const struct cea_db *db)
 {
 	return cea_db_is_extended_tag(db, CTA_EXT_DB_VIDEO_CAP) &&
 		cea_db_payload_len(db) == 2;
 }
 
-static bool cea_db_is_hdmi_forum_scdb(const void *db)
+static bool cea_db_is_hdmi_forum_scdb(const struct cea_db *db)
 {
 	return cea_db_is_extended_tag(db, CTA_EXT_DB_HF_SCDB) &&
 		cea_db_payload_len(db) >= 7;
 }
 
-static bool cea_db_is_y420cmdb(const void *db)
+static bool cea_db_is_y420cmdb(const struct cea_db *db)
 {
 	return cea_db_is_extended_tag(db, CTA_EXT_DB_420_VIDEO_CAP_MAP);
 }
 
-static bool cea_db_is_y420vdb(const void *db)
+static bool cea_db_is_y420vdb(const struct cea_db *db)
 {
 	return cea_db_is_extended_tag(db, CTA_EXT_DB_420_VIDEO_DATA);
 }
 
-static bool cea_db_is_hdmi_hdr_metadata_block(const void *db)
+static bool cea_db_is_hdmi_hdr_metadata_block(const struct cea_db *db)
 {
 	return cea_db_is_extended_tag(db, CTA_EXT_DB_HDR_STATIC_METADATA) &&
 		cea_db_payload_len(db) >= 3;
-- 
2.30.2

[PATCH 16/19] drm/edid: detect basic audio in all CEA extensions

[Jani Nikula]

Convert drm_find_cea_extension() to EDID block iterator in basic audio
detection. Detect basic audio in all CEA extensions.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
 drivers/gpu/drm/drm_edid.c | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 1fc4e8754cd4..091f68102f77 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -5136,17 +5136,21 @@ EXPORT_SYMBOL(drm_detect_hdmi_monitor);
  */
 bool drm_detect_monitor_audio(const struct edid *edid)
 {
+	struct drm_edid_iter edid_iter;
 	const struct cea_db *db;
 	struct cea_db_iter iter;
 	const u8 *edid_ext;
 	bool has_audio = false;
 
-	edid_ext = drm_find_cea_extension(edid);
-	if (!edid_ext)
-		goto end;
-
-	has_audio = (edid_ext[0] == CEA_EXT &&
-		    (edid_ext[3] & EDID_BASIC_AUDIO) != 0);
+	drm_edid_iter_begin(edid, &edid_iter);
+	drm_edid_iter_for_each(edid_ext, &edid_iter) {
+		if (edid_ext[0] == CEA_EXT) {
+			has_audio = edid_ext[3] & EDID_BASIC_AUDIO;
+			if (has_audio)
+				break;
+		}
+	}
+	drm_edid_iter_end(&edid_iter);
 
 	if (has_audio) {
 		DRM_DEBUG_KMS("Monitor has basic audio support\n");
-- 
2.30.2

[PATCH 17/19] drm/edid: detect color formats and CTA revision in all CTA extensions

[Jani Nikula]

Convert drm_find_cea_extension() to EDID block iterator in color format
and CTA revision detection. Detect them in all CTA extensions.

Also parse CTA Data Blocks in DisplayID even if there's no CTA EDID
extension.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
 drivers/gpu/drm/drm_edid.c | 24 ++++++++++++++++--------
 1 file changed, 16 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 091f68102f77..fad9fd13937b 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -5470,32 +5470,40 @@ static void drm_parse_cea_ext(struct drm_connector *connector,
 			      const struct edid *edid)
 {
 	struct drm_display_info *info = &connector->display_info;
+	struct drm_edid_iter edid_iter;
 	const struct cea_db *db;
 	struct cea_db_iter iter;
 	const u8 *edid_ext;
 
-	edid_ext = drm_find_cea_extension(edid);
-	if (!edid_ext)
-		return;
+	drm_edid_iter_begin(edid, &edid_iter);
+	drm_edid_iter_for_each(edid_ext, &edid_iter) {
+		if (edid_ext[0] != CEA_EXT)
+			continue;
 
-	info->cea_rev = edid_ext[1];
+		if (!info->cea_rev)
+			info->cea_rev = edid_ext[1];
 
-	/* The existence of a CEA block should imply RGB support */
-	info->color_formats = DRM_COLOR_FORMAT_RGB444;
+		if (info->cea_rev != edid_ext[1])
+			DRM_DEBUG_KMS("CEA extension version mismatch %u != %u\n",
+				      info->cea_rev, edid_ext[1]);
 
-	/* CTA DisplayID Data Block does not have byte #3 */
-	if (edid_ext[0] == CEA_EXT) {
+		/* The existence of a CTA extension should imply RGB support */
+		info->color_formats = DRM_COLOR_FORMAT_RGB444;
 		if (edid_ext[3] & EDID_CEA_YCRCB444)
 			info->color_formats |= DRM_COLOR_FORMAT_YCBCR444;
 		if (edid_ext[3] & EDID_CEA_YCRCB422)
 			info->color_formats |= DRM_COLOR_FORMAT_YCBCR422;
 	}
+	drm_edid_iter_end(&edid_iter);
 
 	cea_db_iter_edid_begin(edid, &iter);
 	cea_db_iter_for_each(db, &iter) {
 		/* FIXME: convert parsers to use struct cea_db */
 		const u8 *data = (const u8 *)db;
 
+		/* The existence of a CTA block should imply RGB support */
+		info->color_formats = DRM_COLOR_FORMAT_RGB444;
+
 		if (cea_db_is_hdmi_vsdb(db))
 			drm_parse_hdmi_vsdb_video(connector, data);
 		if (cea_db_is_hdmi_forum_vsdb(db) ||
-- 
2.30.2

[PATCH 18/19] drm/edid: skip CTA extension scan in drm_edid_to_eld() just for CTA rev

[Jani Nikula]

The DisplayID CTA data block version does not necessarily match the CTA
revision. Simplify by postponing drm_edid_to_eld() slightly, and reusing
the CTA revision extracted by drm_parse_cea_ext().

By not bailing out early in drm_edid_to_eld() we may end up filling
meaningless data to the ELD. However, the main decision for audio is not
the ELD, but rather drm_detect_monitor_audio() called by drivers.

(Arguably a future cleanup could do that in drm_add_edid_modes() and
cache the result in the connector.)

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
 drivers/gpu/drm/drm_edid.c | 15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index fad9fd13937b..ccd7d075eeb8 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -4887,10 +4887,10 @@ static void clear_eld(struct drm_connector *connector)
 static void drm_edid_to_eld(struct drm_connector *connector,
 			    const struct edid *edid)
 {
+	const struct drm_display_info *info = &connector->display_info;
 	const struct cea_db *db;
 	struct cea_db_iter iter;
 	uint8_t *eld = connector->eld;
-	const u8 *cea;
 	int total_sad_count = 0;
 	int mnl;
 
@@ -4899,16 +4899,10 @@ static void drm_edid_to_eld(struct drm_connector *connector,
 	if (!edid)
 		return;
 
-	cea = drm_find_cea_extension(edid);
-	if (!cea) {
-		DRM_DEBUG_KMS("ELD: no CEA Extension found\n");
-		return;
-	}
-
 	mnl = get_monitor_name(edid, &eld[DRM_ELD_MONITOR_NAME_STRING]);
 	DRM_DEBUG_KMS("ELD monitor %s\n", &eld[DRM_ELD_MONITOR_NAME_STRING]);
 
-	eld[DRM_ELD_CEA_EDID_VER_MNL] = cea[1] << DRM_ELD_CEA_EDID_VER_SHIFT;
+	eld[DRM_ELD_CEA_EDID_VER_MNL] = info->cea_rev << DRM_ELD_CEA_EDID_VER_SHIFT;
 	eld[DRM_ELD_CEA_EDID_VER_MNL] |= mnl;
 
 	eld[DRM_ELD_VER] = DRM_ELD_VER_CEA861D;
@@ -5847,8 +5841,6 @@ static int drm_edid_connector_update(struct drm_connector *connector,
 		return 0;
 	}
 
-	drm_edid_to_eld(connector, edid);
-
 	/*
 	 * CEA-861-F adds ycbcr capability map block, for HDMI 2.0 sinks.
 	 * To avoid multiple parsing of same block, lets parse that map
@@ -5856,6 +5848,9 @@ static int drm_edid_connector_update(struct drm_connector *connector,
 	 */
 	quirks = drm_add_display_info(connector, edid);
 
+	/* Depends on info->cea_rev set by drm_add_display_info() above */
+	drm_edid_to_eld(connector, edid);
+
 	/*
 	 * EDID spec says modes should be preferred in this order:
 	 * - preferred detailed mode
-- 
2.30.2

[PATCH 19/19] drm/edid: sunset drm_find_cea_extension()

[Jani Nikula]

Convert drm_find_cea_extension() to a predicate function to check if the
EDID has a CTA extension or a DisplayID CTA data block. This is mainly
to avoid adding new users that only find the first CTA extension.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
 drivers/gpu/drm/drm_edid.c | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index ccd7d075eeb8..4eeea4212f3a 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -3582,30 +3582,29 @@ const u8 *drm_find_edid_extension(const struct edid *edid,
 	return edid_ext;
 }
 
-static const u8 *drm_find_cea_extension(const struct edid *edid)
+/* Return true if the EDID has a CTA extension or a DisplayID CTA data block */
+static bool drm_edid_has_cta_extension(const struct edid *edid)
 {
 	const struct displayid_block *block;
 	struct displayid_iter iter;
-	const u8 *cea;
 	int ext_index = 0;
+	bool found = false;
 
 	/* 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);
-	if (cea)
-		return cea;
+	if (drm_find_edid_extension(edid, CEA_EXT, &ext_index))
+		return true;
 
 	/* CEA blocks can also be found embedded in a DisplayID block */
 	displayid_iter_edid_begin(edid, &iter);
 	displayid_iter_for_each(block, &iter) {
 		if (block->tag == DATA_BLOCK_CTA) {
-			cea = (const u8 *)block;
+			found = true;
 			break;
 		}
 	}
 	displayid_iter_end(&iter);
 
-	return cea;
+	return found;
 }
 
 static __always_inline const struct drm_display_mode *cea_mode_for_vic(u8 vic)
@@ -3878,8 +3877,8 @@ add_alternate_cea_modes(struct drm_connector *connector, const struct edid *edid
 	LIST_HEAD(list);
 	int modes = 0;
 
-	/* Don't add CEA modes if the CEA extension block is missing */
-	if (!drm_find_cea_extension(edid))
+	/* Don't add CTA modes if the CTA extension block is missing */
+	if (!drm_edid_has_cta_extension(edid))
 		return 0;
 
 	/*
-- 
2.30.2

Re: [PATCH 01/19] drm/edid: reset display info in drm_add_edid_modes() for NULL edid

[Ville Syrjälä]

On Thu, Apr 14, 2022 at 06:06:44PM +0300, Jani Nikula wrote:
> If a NULL edid gets passed to drm_add_edid_modes(), we should probably
> also reset the display info.

One concern I had with this is resetting of eg. {width,height}_mm
which might have been populated by intel_panel_add_fixed_mode().
But I think that might already happen anyway through one of the
other codepaths that call drm_reset_display_info() so probably not
something that is made any worse by this patch.

IIRC at one point I tried to startd cleaning up the display_info
mess a bit but the patches got stuck in some silly bikeshed
so I gave up.

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

> 
> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
> ---
>  drivers/gpu/drm/drm_edid.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
> index 324ce8467915..4758e78fad82 100644
> --- a/drivers/gpu/drm/drm_edid.c
> +++ b/drivers/gpu/drm/drm_edid.c
> @@ -5721,6 +5721,7 @@ static int drm_edid_connector_update(struct drm_connector *connector,
>  	u32 quirks;
>  
>  	if (edid == NULL) {
> +		drm_reset_display_info(connector);
>  		clear_eld(connector);
>  		return 0;
>  	}
> -- 
> 2.30.2

-- 
Ville Syrjälä
Intel

Re: [PATCH 02/19] drm/edid: check for HF-SCDB block

[Ville Syrjälä]

On Thu, Apr 14, 2022 at 06:06:45PM +0300, Jani Nikula wrote:
> From: Lee Shawn C <shawn.c.lee@intel.com>
> 
> Find HF-SCDB information in CEA extensions block. And retrieve
> Max_TMDS_Character_Rate that support by sink device.
> 
> v2: HF-SCDB and HF-VSDBS carry the same SCDS data. Reuse
>     drm_parse_hdmi_forum_vsdb() to parse this packet.
> 
> Cc: Jani Nikula <jani.nikula@linux.intel.com>
> Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
> Cc: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
> Cc: intel-gfx <intel-gfx@lists.freedesktop.org>
> Signed-off-by: Lee Shawn C <shawn.c.lee@intel.com>
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
> ---
>  drivers/gpu/drm/drm_edid.c | 18 +++++++++++++++++-
>  1 file changed, 17 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
> index 4758e78fad82..32ece9607b94 100644
> --- a/drivers/gpu/drm/drm_edid.c
> +++ b/drivers/gpu/drm/drm_edid.c
> @@ -3495,6 +3495,7 @@ add_detailed_modes(struct drm_connector *connector, const struct edid *edid,
>  #define EXT_VIDEO_CAPABILITY_BLOCK 0x00
>  #define EXT_VIDEO_DATA_BLOCK_420	0x0E
>  #define EXT_VIDEO_CAP_BLOCK_Y420CMDB 0x0F
> +#define EXT_VIDEO_HF_SCDB_DATA_BLOCK	0x79
>  #define EDID_BASIC_AUDIO	(1 << 6)
>  #define EDID_CEA_YCRCB444	(1 << 5)
>  #define EDID_CEA_YCRCB422	(1 << 4)
> @@ -4426,6 +4427,20 @@ static bool cea_db_is_vcdb(const u8 *db)
>  	return true;
>  }
>  
> +static bool cea_db_is_hdmi_forum_scdb(const u8 *db)
> +{
> +	if (cea_db_tag(db) != USE_EXTENDED_TAG)
> +		return false;
> +
> +	if (cea_db_payload_len(db) < 7)
> +		return false;
> +
> +	if (cea_db_extended_tag(db) != EXT_VIDEO_HF_SCDB_DATA_BLOCK)
> +		return false;
> +
> +	return true;
> +}
> +
>  static bool cea_db_is_y420cmdb(const u8 *db)
>  {
>  	if (cea_db_tag(db) != USE_EXTENDED_TAG)
> @@ -5387,7 +5402,8 @@ static void drm_parse_cea_ext(struct drm_connector *connector,
>  
>  		if (cea_db_is_hdmi_vsdb(db))
>  			drm_parse_hdmi_vsdb_video(connector, db);
> -		if (cea_db_is_hdmi_forum_vsdb(db))
> +		if (cea_db_is_hdmi_forum_vsdb(db) ||
> +		    cea_db_is_hdmi_forum_scdb(db))
>  			drm_parse_hdmi_forum_vsdb(connector, db);

I'd do a s/parse_hdmi_forum_vsdb/parse_scds/ to keep up
with the spec terminology.

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

>  		if (cea_db_is_microsoft_vsdb(db))
>  			drm_parse_microsoft_vsdb(connector, db);
> -- 
> 2.30.2

-- 
Ville Syrjälä
Intel

Re: [PATCH 06/19] drm/edid: clean up cea_db_is_*() functions

[Ville Syrjälä]

On Thu, Apr 14, 2022 at 06:06:49PM +0300, Jani Nikula wrote:
> Abstract helpers for matching vendor data blocks and extended tags, and
> use them to simplify all the cea_db_is_*() functions.
> 
> Take void pointer as parameter to allow transitional use for both u8 *
> and struct cea_db *.
> 
> v2: Remove superfluous parens (Ville)
> 
> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

> ---
>  drivers/gpu/drm/drm_edid.c | 127 ++++++++++++-------------------------
>  1 file changed, 40 insertions(+), 87 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
> index 43d9e04f8fb9..34897b1417a5 100644
> --- a/drivers/gpu/drm/drm_edid.c
> +++ b/drivers/gpu/drm/drm_edid.c
> @@ -4360,12 +4360,6 @@ do_hdmi_vsdb_modes(struct drm_connector *connector, const u8 *db, u8 len,
>  	return modes;
>  }
>  
> -static int
> -cea_db_extended_tag(const u8 *db)
> -{
> -	return db[1];
> -}
> -
>  static int
>  cea_revision(const u8 *cea)
>  {
> @@ -4477,6 +4471,22 @@ static const void *cea_db_data(const struct cea_db *db)
>  	return db->data;
>  }
>  
> +static bool cea_db_is_extended_tag(const struct cea_db *db, int tag)
> +{
> +	return cea_db_tag(db) == CTA_DB_EXTENDED_TAG &&
> +		cea_db_payload_len(db) >= 1 &&
> +		db->data[0] == tag;
> +}
> +
> +static bool cea_db_is_vendor(const struct cea_db *db, int vendor_oui)
> +{
> +	const u8 *data = cea_db_data(db);
> +
> +	return cea_db_tag(db) == CTA_DB_VENDOR &&
> +		cea_db_payload_len(db) >= 3 &&
> +		oui(data[2], data[1], data[0]) == vendor_oui;
> +}
> +
>  static void cea_db_iter_edid_begin(const struct edid *edid, struct cea_db_iter *iter)
>  {
>  	memset(iter, 0, sizeof(*iter));
> @@ -4611,93 +4621,50 @@ static void cea_db_iter_end(struct cea_db_iter *iter)
>  	memset(iter, 0, sizeof(*iter));
>  }
>  
> -static bool cea_db_is_hdmi_vsdb(const u8 *db)
> +static bool cea_db_is_hdmi_vsdb(const void *db)
>  {
> -	if (cea_db_tag(db) != CTA_DB_VENDOR)
> -		return false;
> -
> -	if (cea_db_payload_len(db) < 5)
> -		return false;
> -
> -	return oui(db[3], db[2], db[1]) == HDMI_IEEE_OUI;
> +	return cea_db_is_vendor(db, HDMI_IEEE_OUI) &&
> +		cea_db_payload_len(db) >= 5;
>  }
>  
> -static bool cea_db_is_hdmi_forum_vsdb(const u8 *db)
> +static bool cea_db_is_hdmi_forum_vsdb(const void *db)
>  {
> -	if (cea_db_tag(db) != CTA_DB_VENDOR)
> -		return false;
> -
> -	if (cea_db_payload_len(db) < 7)
> -		return false;
> -
> -	return oui(db[3], db[2], db[1]) == HDMI_FORUM_IEEE_OUI;
> +	return cea_db_is_vendor(db, HDMI_FORUM_IEEE_OUI) &&
> +		cea_db_payload_len(db) >= 7;
>  }
>  
> -static bool cea_db_is_microsoft_vsdb(const u8 *db)
> +static bool cea_db_is_microsoft_vsdb(const void *db)
>  {
> -	if (cea_db_tag(db) != CTA_DB_VENDOR)
> -		return false;
> -
> -	if (cea_db_payload_len(db) != 21)
> -		return false;
> -
> -	return oui(db[3], db[2], db[1]) == MICROSOFT_IEEE_OUI;
> +	return cea_db_is_vendor(db, MICROSOFT_IEEE_OUI) &&
> +		cea_db_payload_len(db) == 21;
>  }
>  
> -static bool cea_db_is_vcdb(const u8 *db)
> +static bool cea_db_is_vcdb(const void *db)
>  {
> -	if (cea_db_tag(db) != CTA_DB_EXTENDED_TAG)
> -		return false;
> -
> -	if (cea_db_payload_len(db) != 2)
> -		return false;
> -
> -	if (cea_db_extended_tag(db) != CTA_EXT_DB_VIDEO_CAP)
> -		return false;
> -
> -	return true;
> +	return cea_db_is_extended_tag(db, CTA_EXT_DB_VIDEO_CAP) &&
> +		cea_db_payload_len(db) == 2;
>  }
>  
> -static bool cea_db_is_hdmi_forum_scdb(const u8 *db)
> +static bool cea_db_is_hdmi_forum_scdb(const void *db)
>  {
> -	if (cea_db_tag(db) != CTA_DB_EXTENDED_TAG)
> -		return false;
> -
> -	if (cea_db_payload_len(db) < 7)
> -		return false;
> -
> -	if (cea_db_extended_tag(db) != CTA_EXT_DB_HF_SCDB)
> -		return false;
> -
> -	return true;
> +	return cea_db_is_extended_tag(db, CTA_EXT_DB_HF_SCDB) &&
> +		cea_db_payload_len(db) >= 7;
>  }
>  
> -static bool cea_db_is_y420cmdb(const u8 *db)
> +static bool cea_db_is_y420cmdb(const void *db)
>  {
> -	if (cea_db_tag(db) != CTA_DB_EXTENDED_TAG)
> -		return false;
> -
> -	if (!cea_db_payload_len(db))
> -		return false;
> -
> -	if (cea_db_extended_tag(db) != CTA_EXT_DB_420_VIDEO_CAP_MAP)
> -		return false;
> -
> -	return true;
> +	return cea_db_is_extended_tag(db, CTA_EXT_DB_420_VIDEO_CAP_MAP);
>  }
>  
> -static bool cea_db_is_y420vdb(const u8 *db)
> +static bool cea_db_is_y420vdb(const void *db)
>  {
> -	if (cea_db_tag(db) != CTA_DB_EXTENDED_TAG)
> -		return false;
> -
> -	if (!cea_db_payload_len(db))
> -		return false;
> -
> -	if (cea_db_extended_tag(db) != CTA_EXT_DB_420_VIDEO_DATA)
> -		return false;
> +	return cea_db_is_extended_tag(db, CTA_EXT_DB_420_VIDEO_DATA);
> +}
>  
> -	return true;
> +static bool cea_db_is_hdmi_hdr_metadata_block(const void *db)
> +{
> +	return cea_db_is_extended_tag(db, CTA_EXT_DB_HDR_STATIC_METADATA) &&
> +		cea_db_payload_len(db) >= 3;
>  }
>  
>  #define for_each_cea_db(cea, i, start, end) \
> @@ -4833,20 +4800,6 @@ static void fixup_detailed_cea_mode_clock(struct drm_display_mode *mode)
>  	mode->clock = clock;
>  }
>  
> -static bool cea_db_is_hdmi_hdr_metadata_block(const u8 *db)
> -{
> -	if (cea_db_tag(db) != CTA_DB_EXTENDED_TAG)
> -		return false;
> -
> -	if (db[1] != CTA_EXT_DB_HDR_STATIC_METADATA)
> -		return false;
> -
> -	if (cea_db_payload_len(db) < 3)
> -		return false;
> -
> -	return true;
> -}
> -
>  static uint8_t eotf_supported(const u8 *edid_ext)
>  {
>  	return edid_ext[2] &
> -- 
> 2.30.2

-- 
Ville Syrjälä
Intel