From: "Timo Prömer" <timo.proemer04@gmail.com>
To: "Harry Wentland" <harry.wentland@amd.com>,
"Leo Li" <sunpeng.li@amd.com>,
"Alex Deucher" <alexander.deucher@amd.com>,
"Christian König" <christian.koenig@amd.com>,
"David Airlie" <airlied@gmail.com>,
"Simona Vetter" <simona@ffwll.ch>
Cc: Rodrigo Siqueira <siqueira@igalia.com>,
Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
Maxime Ripard <mripard@kernel.org>,
Thomas Zimmermann <tzimmermann@suse.de>,
amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
linux-kernel@vger.kernel.org,
Timoyoungster <timo.proemer04@gmail.com>
Subject: [PATCH v2 1/2] drm/edid: Export drm_edid_block_count()
Date: Mon, 13 Jul 2026 21:32:36 +0200 [thread overview]
Message-ID: <20260713193237.2639-2-timo.proemer04@gmail.com> (raw)
In-Reply-To: <20260713193237.2639-1-timo.proemer04@gmail.com>
From: Timoyoungster <timo.proemer04@gmail.com>
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 <timo.proemer04@gmail.com>
---
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
next prev parent reply other threads:[~2026-07-13 19:33 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-13 19:32 [PATCH v2 0/2] drm/amd/display: Fix missing HF-EEODB blocks in EDID copies Timo Prömer
2026-07-13 19:32 ` Timo Prömer [this message]
2026-07-13 19:32 ` [PATCH v2 2/2] drm/amd/display: Use drm_edid_block_count() instead of raw extensions Timo Prömer
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20260713193237.2639-2-timo.proemer04@gmail.com \
--to=timo.proemer04@gmail.com \
--cc=airlied@gmail.com \
--cc=alexander.deucher@amd.com \
--cc=amd-gfx@lists.freedesktop.org \
--cc=christian.koenig@amd.com \
--cc=dri-devel@lists.freedesktop.org \
--cc=harry.wentland@amd.com \
--cc=linux-kernel@vger.kernel.org \
--cc=maarten.lankhorst@linux.intel.com \
--cc=mripard@kernel.org \
--cc=simona@ffwll.ch \
--cc=siqueira@igalia.com \
--cc=sunpeng.li@amd.com \
--cc=tzimmermann@suse.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox