This series adds parsing of the Display Device Technology field from
the DisplayID v2.x Display Parameters Data Block (tag 0x21), enabling
panel type detection (LCD/OLED) through a standards-based source.
Previously, amdgpu_dm determined panel type only from AMD VSDB, DPCD
sink extended caps, and a Samsung luminance heuristic. A TODO comment
in dm_set_panel_type() acknowledged the need to also use DisplayID as
a source. This series resolves that by parsing the Display Parameters
block in DRM core and wiring it into amdgpu_dm's detection priority
chain as: VSDB > DPCD > DisplayID > Samsung heuristic.
Patch 1 extracts the base section header processing into a helper and
removes the break so the iterator can walk through all data blocks.
The helper is invoked only once via a base_section_header_processed
flag because displayid_version() and displayid_primary_use() always
return values captured from the base section — they are fixed
regardless of which extension section the iterator is currently in,
so processing the header more than once would be redundant.
Changes in v3:
- Renamed helper to drm_displayid_process_base_section_header() to
reflect it handles the base section (Jani)
- Fixed argument alignment to match opening parenthesis (Jani)
- Renamed header_processed to base_section_header_processed (Jani)
- Fully expanded displayid_display_params_block struct with all named
fields per spec Table 4-7, replacing u8 payload[27] (Jani)
- Added DISPLAYID_DEVICE_TECH_{UNSPECIFIED,LCD,OLED} named defines (Jani)
- Removed DISPLAYID_DISPLAY_PARAMS_MIN_LEN macro, use inline sizeof (Jani)
- Removed superfluous blank line and useless inline comments (Jani)
- Debug print now shows "LCD"/"OLED" string instead of number (Jani)
- Renamed did_panel_type to panel_type (Jani)
- Added LCD to drm_panel_type_enum_list[] and property documentation (Jani)
- Added PANEL_TYPE_LCD branch in dm_set_panel_type() property setting
Chenyu Chen (3):
drm/edid: extract base section header processing into helper
drm/edid: parse panel type from DisplayID 2.x Display Parameters
drm/amd/display: use DisplayID panel type in dm_set_panel_type
.../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 16 ++--
drivers/gpu/drm/drm_connector.c | 3 +-
drivers/gpu/drm/drm_displayid_internal.h | 24 ++++++
drivers/gpu/drm/drm_edid.c | 80 +++++++++++++++----
include/drm/drm_connector.h | 6 ++
include/uapi/drm/drm_mode.h | 1 +
6 files changed, 109 insertions(+), 21 deletions(-)
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2.43.0
