From: Fangzhi Zuo Date: Wed, 24 Jun 2026 20:54:30 +0000 (-0400) Subject: drm/amd/display: Fix 8K Mode Not Parsed by EDID X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=9b3aa1dec7c364b0d7b171dcc00ab1092e362aef;p=thirdparty%2Fkernel%2Flinux.git drm/amd/display: Fix 8K Mode Not Parsed by EDID [why] The 8K120/8K240 timings live in DisplayID extension blocks 2 and 3 of this EDID. The EDID is a 4-block (512-byte) HDMI 2.1 EDID that uses HF-EEODB. drm core reads and parses this correctly, but amdgpu rebuilds its own copy. Only 2 of 4 blocks were copied into sink->dc_edid, that leads to drm_edid_connector_add_modes() never sees blocks 2 and 3. [how] Directly populate edid_blob_ptr with a blob whose length is the full, and HF-EEODB-aware size. Reviewed-by: Sun peng (Leo) Li Signed-off-by: Fangzhi Zuo Signed-off-by: George Zhang Signed-off-by: Alex Deucher (cherry picked from commit 11a90eaf5c808ba800249dda0d481c35d0888589) --- diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c index c6f94eb71ffa..6be7f6edd0b2 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c @@ -1201,11 +1201,25 @@ enum dc_edid_status dm_helpers_read_local_edid( continue; edid = drm_edid_raw(drm_edid); // FIXME: Get rid of drm_edid_raw() - if (!edid || - edid->extensions >= sizeof(sink->dc_edid.raw_edid) / EDID_LENGTH) + /* + * Use the length of the EDID property blob populated by + * drm_edid_connector_update() above. It reflects the true number + * of EDID blocks, including any HDMI Forum EDID Extension Override + * Data Block (HF-EEODB) count, which the raw byte 0x7e extension + * count can hide (e.g. HDMI 8K sinks). + */ + if (!edid || !connector->edid_blob_ptr || + connector->edid_blob_ptr->length > sizeof(sink->dc_edid.raw_edid)) return EDID_BAD_INPUT; - sink->dc_edid.length = EDID_LENGTH * (edid->extensions + 1); + /* + * FIXME: amdgpu_dm today does not consider the HF-EEODB, which + * may contain additional mode info for sinks. This is a + * workaround until dc_edid is refactored out from DC into + * amdgpu_dm's ownership, allowing amdgpu_dm to use drm_edid + * directly + */ + sink->dc_edid.length = connector->edid_blob_ptr->length; memmove(sink->dc_edid.raw_edid, (uint8_t *)edid, sink->dc_edid.length); /* We don't need the original edid anymore */