[v2 3/4] drm/edid: read HF-EEODB ext block
Lee Shawn C
shawn.c.lee at intel.com
Tue Mar 1 08:12:15 UTC 2022
According to HDMI 2.1 spec.
"The HDMI Forum EDID Extension Override Data Block (HF-EEODB)
is utilized by Sink Devices to provide an alternate method to
indicate an EDID Extension Block count larger than 1, while
avoiding the need to present a VESA Block Map in the first
E-EDID Extension Block."
It is a mandatory for HDMI 2.1 protocol compliance as well.
This patch help to know how many HF_EEODB blocks report by sink
and read allo HF_EEODB blocks back.
v2: support to find CEA block, check EEODB block format, and return
available block number in drm_edid_read_hf_eeodb_blk_count().
Cc: Jani Nikula <jani.nikula at linux.intel.com>
Cc: Ville Syrjala <ville.syrjala at linux.intel.com>
Cc: Ankit Nautiyal <ankit.k.nautiyal at intel.com>
Signed-off-by: Lee Shawn C <shawn.c.lee at intel.com>
---
drivers/gpu/drm/drm_connector.c | 8 +++-
drivers/gpu/drm/drm_edid.c | 79 +++++++++++++++++++++++++++++++--
include/drm/drm_edid.h | 2 +-
3 files changed, 82 insertions(+), 7 deletions(-)
diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index a50c82bc2b2f..16011023c12e 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -2129,7 +2129,7 @@ int drm_connector_update_edid_property(struct drm_connector *connector,
const struct edid *edid)
{
struct drm_device *dev = connector->dev;
- size_t size = 0;
+ size_t size = 0, hf_eeodb_blk_count;
int ret;
const struct edid *old_edid;
@@ -2137,8 +2137,12 @@ int drm_connector_update_edid_property(struct drm_connector *connector,
if (connector->override_edid)
return 0;
- if (edid)
+ if (edid) {
size = EDID_LENGTH * (1 + edid->extensions);
+ hf_eeodb_blk_count = drm_edid_read_hf_eeodb_blk_count(edid);
+ if (hf_eeodb_blk_count)
+ size = EDID_LENGTH * (1 + hf_eeodb_blk_count);
+ }
/* Set the display info, using edid if available, otherwise
* resetting the values to defaults. This duplicates the work
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index e2cfde02f837..8e6e25b52e44 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -1992,6 +1992,7 @@ struct edid *drm_do_get_edid(struct drm_connector *connector,
{
int i, j = 0, valid_extensions = 0;
u8 *edid, *new;
+ size_t hf_eeodb_blk_count;
struct edid *override;
override = drm_get_override_edid(connector);
@@ -2051,7 +2052,39 @@ struct edid *drm_do_get_edid(struct drm_connector *connector,
}
kfree(edid);
+ return (struct edid *)new;
+ }
+
+ hf_eeodb_blk_count = drm_edid_read_hf_eeodb_blk_count((struct edid *)edid);
+ if (hf_eeodb_blk_count) {
+ // no more ext blk wait for read
+ if (hf_eeodb_blk_count <= 1)
+ return (struct edid *)edid;
+
+ new = krealloc(edid, (hf_eeodb_blk_count + 1) * EDID_LENGTH, GFP_KERNEL);
+ if (!new)
+ goto out;
edid = new;
+
+ valid_extensions = hf_eeodb_blk_count - 1;
+ for (j = 2; j <= hf_eeodb_blk_count; j++) {
+ u8 *block = edid + j * EDID_LENGTH;
+
+ for (i = 0; i < 4; i++) {
+ if (get_edid_block(data, block, j, EDID_LENGTH))
+ goto out;
+ if (drm_edid_block_valid(block, j, false, NULL))
+ break;
+ }
+
+ if (i == 4)
+ valid_extensions--;
+ }
+
+ if (valid_extensions != hf_eeodb_blk_count - 1) {
+ DRM_ERROR("Not able to retrieve proper EDID contain HF-EEODB data.\n");
+ goto out;
+ }
}
return (struct edid *)edid;
@@ -3315,15 +3348,17 @@ add_detailed_modes(struct drm_connector *connector, struct edid *edid,
#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_CAPABILITY_BLOCK 0x00
+#define HDR_STATIC_METADATA_BLOCK 0x06
+#define USE_EXTENDED_TAG 0x07
#define EXT_VIDEO_DATA_BLOCK_420 0x0E
-#define EXT_VIDEO_CAP_BLOCK_Y420CMDB 0x0F
+#define EXT_VIDEO_CAP_BLOCK_Y420CMDB 0x0F
+#define EXT_VIDEO_HF_EEODB_DATA_BLOCK 0x78
#define EDID_BASIC_AUDIO (1 << 6)
#define EDID_CEA_YCRCB444 (1 << 5)
#define EDID_CEA_YCRCB422 (1 << 4)
#define EDID_CEA_VCDB_QS (1 << 6)
+#define HF_EEODB_LENGTH 2
/*
* Search EDID for CEA extension block.
@@ -4231,6 +4266,20 @@ static bool cea_db_is_microsoft_vsdb(const u8 *db)
return oui(db[3], db[2], db[1]) == MICROSOFT_IEEE_OUI;
}
+static bool cea_db_is_hdmi_forum_eeodb(const u8 *db)
+{
+ if (cea_db_tag(db) != USE_EXTENDED_TAG)
+ return false;
+
+ if (cea_db_payload_len(db) != HF_EEODB_LENGTH)
+ return false;
+
+ if (cea_db_extended_tag(db) != EXT_VIDEO_HF_EEODB_DATA_BLOCK)
+ return false;
+
+ return true;
+}
+
static bool cea_db_is_vcdb(const u8 *db)
{
if (cea_db_tag(db) != USE_EXTENDED_TAG)
@@ -4276,6 +4325,28 @@ static bool cea_db_is_y420vdb(const u8 *db)
#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)
+size_t drm_edid_read_hf_eeodb_blk_count(const struct edid *edid)
+{
+ const u8 *cea;
+ int ext_index = 0;
+
+ if (edid->extensions) {
+ cea = drm_find_cea_extension(edid, &ext_index);
+
+ if (cea) {
+ int i, start, end;
+
+ if (!cea_db_offsets(cea, &start, &end))
+ for_each_cea_db(cea, i, start, end)
+ if (cea_db_is_hdmi_forum_eeodb(&cea[i]))
+ return cea[i + 2];
+ }
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(drm_edid_read_hf_eeodb_blk_count);
+
static void drm_parse_y420cmdb_bitmap(struct drm_connector *connector,
const u8 *db)
{
diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h
index 144c495b99c4..5549da7bd7be 100644
--- a/include/drm/drm_edid.h
+++ b/include/drm/drm_edid.h
@@ -592,6 +592,6 @@ drm_display_mode_from_cea_vic(struct drm_device *dev,
u8 video_code);
const u8 *drm_find_edid_extension(const struct edid *edid,
int ext_id, int *ext_index);
-
+size_t drm_edid_read_hf_eeodb_blk_count(const struct edid *edid);
#endif /* __DRM_EDID_H__ */
--
2.31.1
More information about the dri-devel
mailing list