DRM's EDID read helpers probe DDC before consulting debugfs or firmware overrides. This preserves connector-detection semantics for drivers that use a successful EDID read as evidence that a sink is connected, but it prevents drivers with independent presence detection from using an override when DDC is unresponsive.
This affects AMD Display Core, which establishes physical presence from HPD before attempting to read the EDID. When a connected sink stops responding over DDC, the configured override is ignored and AMDGPU falls back to a 640x480 mode. Add an override-only EDID reader that does not access hardware, then use it in AMD Display Core before trying ACPI, VBIOS, or DDC sources. The new helper preserves DRM_FORCE_OFF handling and the existing preference for debugfs overrides over firmware EDIDs. The first patch introduces the helper. The second fixes the AMDGPU regression. Mario Limonciello (2): drm/edid: Add an override-only EDID reader drm/amd/display: Honor EDID overrides for connected sinks .../amd/display/amdgpu_dm/amdgpu_dm_helpers.c | 14 +++++++----- drivers/gpu/drm/drm_edid.c | 22 +++++++++++++++++++ include/drm/drm_edid.h | 1 + 3 files changed, 32 insertions(+), 5 deletions(-) -- 2.43.0
