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

Limonciello, Mario Mario.Limonciello at amd.com
Tue Aug 12 19:30:42 UTC 2025


On 8/11/25 4:26 PM, Wentland, Harry wrote:
> 
> 
> On 2025-08-11 17:09, Limonciello, Mario wrote:
>> On 8/11/25 4:08 PM, Hung, Alex wrote:
>>> Melissa,
>>>
>>> The patchset passed promotion and CI.
>>>
>>> However, since our DC code is shared with the other OS, calling drm_*
>>> functions in DC won't work for us. For example, calling
>>> dc_edid_copy_edid_to_sink from dc/link/link_detection.c in patch 14.
>>>
>>> I don't have a good way to handle it. Does it make sense not to touch DC
>>> code for now?
>>
>> What about if we have a set of compatibility macros in DC code?
>>
>> Something like this:
>>
>> #ifndef drm_dbg
>> #define drm_dbg ....
>> #endif
> 
> DC should stay OS-agnostic. No DRM concepts in DC please.
> 
> Why the need to change dc_edid_is_same_edid?
> 
> I'll comment directly on the patch.
> 
> Harry

I hadn't dug into the patches to realize that this was more than just 
debug prints.  I figured for those using a macro would be fine, but more 
in depth stuff totally aligned with you.

> 
>>>
>>> On 8/11/25 13:40, Melissa Wen wrote:
>>>>
>>>>
>>>> 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 at 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 at 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 at 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 at 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 at 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 at 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
>>>>>>
>>>>>
>>>>
>>>
>>
> 



More information about the dri-devel mailing list