Drivers currently calculating EDID size by reading the `extensions`
field of the raw EDID structure (e.g., `edid->extensions + 1`) will
calculate the wrong size if the EDID contains an HF-EEODB (HDMI Forum
EDID Extension Override Data Block). The base extension flag does not
account for these override blocks, leading to truncated EDIDs.

Remove the static declaration and export drm_edid_block_count() so
drivers can safely query the true block count. This allows drivers to
leverage the core DRM's proper handling of HF-EEODB and other edge
cases without having to parse the raw EDID fields themselves.

Signed-off-by: Timo Prömer <[email protected]>
---
 drivers/gpu/drm/drm_edid.c | 3 ++-
 include/drm/drm_edid.h     | 1 +
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index df3c25bac..34560b33a 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -1698,12 +1698,13 @@ static int __drm_edid_block_count(const struct drm_edid 
*drm_edid)
 }
 
 /* EDID block count, limited by allocated size */
-static int drm_edid_block_count(const struct drm_edid *drm_edid)
+int drm_edid_block_count(const struct drm_edid *drm_edid)
 {
        /* Limit by allocated size */
        return min(__drm_edid_block_count(drm_edid),
                   (int)drm_edid->size / EDID_LENGTH);
 }
+EXPORT_SYMBOL(drm_edid_block_count);
 
 /* EDID extension block count, limited by allocated size */
 static int drm_edid_extension_block_count(const struct drm_edid *drm_edid)
diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h
index 04f7a7f1f..4a990bf87 100644
--- a/include/drm/drm_edid.h
+++ b/include/drm/drm_edid.h
@@ -481,6 +481,7 @@ const struct drm_edid *drm_edid_read_switcheroo(struct 
drm_connector *connector,
 int drm_edid_connector_update(struct drm_connector *connector,
                              const struct drm_edid *edid);
 int drm_edid_connector_add_modes(struct drm_connector *connector);
+int drm_edid_block_count(const struct drm_edid *drm_edid);
 bool drm_edid_is_digital(const struct drm_edid *drm_edid);
 void drm_edid_get_product_id(const struct drm_edid *drm_edid,
                             struct drm_edid_product_id *id);
-- 
2.55.0

Reply via email to