[PATCH v6 00/14] drm/amd/display: more drm_edid to AMD display driver

Mon Aug 11 19:40:01 UTC 2025

On 28/07/2025 20:29, Alex Hung wrote:
> Thanks. I will send v6 to promotion test.
Hi Alex,

Any news about this round of tests?

BR,

Melissa

>
> On 7/25/25 18:33, Melissa Wen wrote:
>> Hi,
>>
>> Siqueira and I have been working on a solution to reduce the usage of
>> drm_edid_raw in the AMD display driver, since the current guideline in
>> the DRM subsystem is to stop handling raw edid data in driver-specific
>> implementation and use opaque `drm_edid` object with common-code
>> helpers.
>>
>> To keep DC as an OS-agnostic component, we create a mid layer that
>> isolates `drm_edid` helpers called in the DC code, while allowing other
>> OSes to implement their specific implementation.
>>
>> This work is an extension of [1].
>>
>> - Patch 1 addresses a possible leak added by previous migration to
>>    drm_edid.
>> - Patch 2 allocates a temporary drm_edid from raw edid for parsing.
>> - Patches 3-7 use common-code, drm_edid helpers to parse edid
>>    capabilities instead of driver-specific solutions. For this, patch 4
>>    introduces a new helper that gets monitor name from drm_edid.
>> - Patches 8-9 are groundwork to reduce the noise of Linux/DRM specific
>>    code in the DC shared code
>> - Patch 10 creates a mid layer to make DC embraces different ways of
>>    handling EDID by platforms.
>> - Patch 11 move open-coded management of raw EDID data to the mid
>>    layer created before.
>> - Patch 12 introduces a helper that compares EDIDs from two drm_edids.
>> - Patch 13 adds drm_edid to dc_sink struct and a mid-layer helper to
>>    free `drm_edid`.
>> - Patch 14 switch dc_edid to drm_edid across the driver in a way that
>>    the DC shared code is little affected by Linux specific stuff.
>>
>> [v1] 
>> https://lore.kernel.org/dri-devel/20250411201333.151335-1-mwen@igalia.com/
>> Changes:
>> - fix broken approach to get monitor name from eld (Jani)
>>    - I introduced a new helper that gets monitor name from drm_edid
>> - rename drm_edid_eq to drm_edid_eq_buf and doc fixes (Jani)
>> - add NULL edid checks (Jani)
>> - fix mishandling of product_id.manufacturer_name (Michel)
>>    - I directly set it to manufacturer_id since sparse didn't complain.
>> - add Mario's r-b in the first fix patch and fix commit msg typo.
>>
>> [v2] 
>> https://lore.kernel.org/dri-devel/20250507001712.120215-1-mwen@igalia.com/
>> Changes:
>> - kernel-doc and commit msg fixes (Jani)
>> - use drm_edid_legacy_init instead of open coded (Jani)
>> - place drm_edid new func into the right section (Jani)
>> - paramenter names fix (Jani)
>> - add Jani's r-b to the patch 12
>> - remove unnecessary include (Jani)
>> - call dc_edid_sink_edid_free in link_detection, instead of 
>> drm_edid_free
>> - rebase on top of asdn
>>
>> [v3] 
>> https://lore.kernel.org/dri-devel/20250514202130.291324-1-mwen@igalia.com/
>> Changes:
>> - rebase to asdn
>> - some kernel-doc fixes
>> - move some changes to the right commit
>>
>> [v4] 
>> https://lore.kernel.org/amd-gfx/20250613150015.245917-1-mwen@igalia.com/
>> Changes:
>> - fix comments and commit messages (Mario)
>> - remove unnecessary drm_edid dup and fix mem leak (Mario)
>> - add Mario's rb to patches 5-7
>>
>> [v5] 
>> https://lore.kernel.org/amd-gfx/20250618152216.948406-1-mwen@igalia.com/
>> Changes:
>> - fix NULL pointer dereference (Alex H.) with the same approach proposed
>>    by 7c3be3ce3dfae
>>
> > --->
>> There are three specific points where we still use drm_edid_raw() in the
>> driver:
>> 1. raw edid data for write EDID checksum in DP_TEST_EDID_CHECKSUM via
>>     drm_dp_dpcd_write(), that AFAIK there is no common code solution 
>> yet;
>> 2. open-coded connectivity log for dc link detection, that maybe can be
>>     moved to drm (?);
>> 3. open-coded parser that I suspect is a lot of duplicated code, but
>>     needs careful examining.
>>
>> I suggest to address those points in a next phase for regression 
>> control.
>>
>> [1] 
>> https://lore.kernel.org/amd-gfx/20250308142650.35920-1-mwen@igalia.com/
>>
>> Let me know yours thoughts!
>>
>> Melissa
>>
>> Melissa Wen (12):
>>    drm/amd/display: make sure drm_edid stored in aconnector doesn't leak
>>    drm/amd/display: start using drm_edid helpers to parse EDID caps
>>    drm/amd/display: use drm_edid_product_id for parsing EDID product 
>> info
>>    drm/edid: introduce a helper that gets monitor name from drm_edid
>>    drm/amd/display: get panel id with drm_edid helper
>>    drm/amd/display: get SAD from drm_eld when parsing EDID caps
>>    drm/amd/display: get SADB from drm_eld when parsing EDID caps
>>    drm/amd/display: simplify dm_helpers_parse_edid_caps signature
>>    drm/amd/display: change DC functions to accept private types for edid
>>    drm/edid: introduce a helper that compares edid data from two 
>> drm_edid
>>    drm/amd/display: add drm_edid to dc_sink
>>    drm/amd/display: move dc_sink from dc_edid to drm_edid
>>
>> Rodrigo Siqueira (2):
>>    drm/amd/display: add a mid-layer file to handle EDID in DC
>>    drm/amd/display: create a function to fill dc_sink with edid data
>>
>>   .../gpu/drm/amd/display/amdgpu_dm/Makefile    |   1 +
>>   .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c |  33 +++---
>>   .../amd/display/amdgpu_dm/amdgpu_dm_helpers.c | 109 +++++++-----------
>>   .../display/amdgpu_dm/amdgpu_dm_mst_types.c   |  21 ++--
>>   .../gpu/drm/amd/display/amdgpu_dm/dc_edid.c   |  39 +++++++
>>   .../gpu/drm/amd/display/amdgpu_dm/dc_edid.h   |  15 +++
>>   .../drm/amd/display/dc/core/dc_link_exports.c |   9 +-
>>   drivers/gpu/drm/amd/display/dc/core/dc_sink.c |   3 +
>>   drivers/gpu/drm/amd/display/dc/dc.h           |  10 +-
>>   drivers/gpu/drm/amd/display/dc/dm_helpers.h   |   7 +-
>>   drivers/gpu/drm/amd/display/dc/inc/link.h     |   9 +-
>>   .../drm/amd/display/dc/link/link_detection.c  |  30 ++---
>>   .../drm/amd/display/dc/link/link_detection.h  |   9 +-
>>   drivers/gpu/drm/bridge/sil-sii8620.c          |   2 +-
>>   drivers/gpu/drm/display/drm_dp_mst_topology.c |   2 +-
>>   drivers/gpu/drm/drm_edid.c                    |  54 +++++++--
>>   include/drm/drm_edid.h                        |  10 +-
>>   17 files changed, 199 insertions(+), 164 deletions(-)
>>   create mode 100644 drivers/gpu/drm/amd/display/amdgpu_dm/dc_edid.c
>>   create mode 100644 drivers/gpu/drm/amd/display/amdgpu_dm/dc_edid.h
>>
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