HDMI 2.1 section 10.3.6 defines an HDMI Forum EDID Extension Override Data Block, which may contain a different extension count than the base block claims. Add support for reading more EDID data if available. The extra blocks aren't parsed yet, though.
Hard-coding the EEODB parsing instead of using the iterators we have is a bit of a bummer, but we have to be able to do this on a partially allocated EDID while reading it.
v2: - Check for CEA Data Block Collection size (Ville) - Amend commit message and comment about hard-coded parsing
Signed-off-by: Jani Nikula jani.nikula@intel.com Reviewed-by: Ville Syrjälä ville.syrjala@linux.intel.com --- drivers/gpu/drm/drm_edid.c | 89 ++++++++++++++++++++++++++++++++++++-- 1 file changed, 86 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c index a80ea0aa7b32..fa3a3e294560 100644 --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -1581,6 +1581,15 @@ static bool version_greater(const struct drm_edid *drm_edid, (edid->version == version && edid->revision > revision); }
+static int edid_hfeeodb_extension_block_count(const struct edid *edid); + +static int edid_hfeeodb_block_count(const struct edid *edid) +{ + int eeodb = edid_hfeeodb_extension_block_count(edid); + + return eeodb ? eeodb + 1 : 0; +} + static int edid_extension_block_count(const struct edid *edid) { return edid->extensions; @@ -2026,6 +2035,11 @@ static struct edid *edid_filter_invalid_blocks(struct edid *edid, struct edid *new; int i, valid_blocks = 0;
+ /* + * Note: If the EDID uses HF-EEODB, but has invalid blocks, we'll revert + * back to regular extension count here. We don't want to start + * modifying the HF-EEODB extension too. + */ for (i = 0; i < edid_block_count(edid); i++) { const void *src_block = edid_block_data(edid, i);
@@ -2261,7 +2275,7 @@ static struct edid *_drm_do_get_edid(struct drm_connector *connector, size_t *size) { enum edid_block_status status; - int i, invalid_blocks = 0; + int i, num_blocks, invalid_blocks = 0; struct edid *edid, *new; size_t alloc_size = EDID_LENGTH;
@@ -2303,7 +2317,8 @@ static struct edid *_drm_do_get_edid(struct drm_connector *connector, goto fail; edid = new;
- for (i = 1; i < edid_block_count(edid); i++) { + num_blocks = edid_block_count(edid); + for (i = 1; i < num_blocks; i++) { void *block = (void *)edid_block_data(edid, i);
status = edid_block_read(block, i, read_block, context); @@ -2314,11 +2329,31 @@ static struct edid *_drm_do_get_edid(struct drm_connector *connector, if (status == EDID_BLOCK_READ_FAIL) goto fail; invalid_blocks++; + } else if (i == 1) { + /* + * If the first EDID extension is a CTA extension, and + * the first Data Block is HF-EEODB, override the + * extension block count. + * + * Note: HF-EEODB could specify a smaller extension + * count too, but we can't risk allocating a smaller + * amount. + */ + int eeodb = edid_hfeeodb_block_count(edid); + + if (eeodb > num_blocks) { + num_blocks = eeodb; + alloc_size = edid_size_by_blocks(num_blocks); + new = krealloc(edid, alloc_size, GFP_KERNEL); + if (!new) + goto fail; + edid = new; + } } }
if (invalid_blocks) { - connector_bad_edid(connector, edid, edid_block_count(edid)); + connector_bad_edid(connector, edid, num_blocks);
edid = edid_filter_invalid_blocks(edid, &alloc_size); } @@ -3851,6 +3886,7 @@ static int add_detailed_modes(struct drm_connector *connector, #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_EEODB 0x78 #define CTA_EXT_DB_HF_SCDB 0x79
#define EDID_BASIC_AUDIO (1 << 6) @@ -4910,6 +4946,12 @@ static bool cea_db_is_hdmi_forum_vsdb(const struct cea_db *db) cea_db_payload_len(db) >= 7; }
+static bool cea_db_is_hdmi_forum_eeodb(const void *db) +{ + return cea_db_is_extended_tag(db, CTA_EXT_DB_HF_EEODB) && + cea_db_payload_len(db) >= 2; +} + static bool cea_db_is_microsoft_vsdb(const struct cea_db *db) { return cea_db_is_vendor(db, MICROSOFT_IEEE_OUI) && @@ -4944,6 +4986,47 @@ static bool cea_db_is_hdmi_hdr_metadata_block(const struct cea_db *db) cea_db_payload_len(db) >= 3; }
+/* + * Get the HF-EEODB override extension block count from EDID. + * + * The passed in EDID may be partially read, as long as it has at least two + * blocks (base block and one extension block) if EDID extension count is > 0. + * + * Note that this is *not* how you should parse CTA Data Blocks in general; this + * is only to handle partially read EDIDs. Normally, use the CTA Data Block + * iterators instead. + * + * References: + * - HDMI 2.1 section 10.3.6 HDMI Forum EDID Extension Override Data Block + */ +static int edid_hfeeodb_extension_block_count(const struct edid *edid) +{ + const u8 *cta; + + /* No extensions according to base block, no HF-EEODB. */ + if (!edid_extension_block_count(edid)) + return 0; + + /* HF-EEODB is always in the first EDID extension block only */ + cta = edid_extension_block_data(edid, 0); + if (edid_block_tag(cta) != CEA_EXT || cea_revision(cta) < 3) + return 0; + + /* Need to have the data block collection, and at least 3 bytes. */ + if (cea_db_collection_size(cta) < 3) + return 0; + + /* + * Sinks that include the HF-EEODB in their E-EDID shall include one and + * only one instance of the HF-EEODB in the E-EDID, occupying bytes 4 + * through 6 of Block 1 of the E-EDID. + */ + if (!cea_db_is_hdmi_forum_eeodb(&cta[4])) + return 0; + + return cta[4 + 2]; +} + static void drm_parse_y420cmdb_bitmap(struct drm_connector *connector, const u8 *db) {