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.nik...@linux.intel.com>
Cc: Ville Syrjala <ville.syrj...@linux.intel.com>
Cc: Ankit Nautiyal <ankit.k.nauti...@intel.com>
Signed-off-by: Lee Shawn C <shawn.c....@intel.com>
---
 drivers/gpu/drm/drm_connector.c |  8 +++-
 drivers/gpu/drm/drm_edid.c      | 71 +++++++++++++++++++++++++++++++--
 include/drm/drm_edid.h          |  2 +-
 3 files changed, 74 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 c4a47465ba76..e5ac9ab0b9d0 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 +2052,35 @@ 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 >= 2) {
+               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 +3344,17 @@ 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.
@@ -4273,9 +4304,41 @@ static bool cea_db_is_y420vdb(const u8 *db)
        return true;
 }
 
+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;
+}
+
 #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 i, start, end, ext_index = 0;
+
+       if (edid->extensions) {
+               cea = drm_find_cea_extension(edid, &ext_index);
+
+               if (cea && !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

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