[PATCH v6 00/14] drm/amd/display: more drm_edid to AMD display driver
Alex Hung
alex.hung at amd.com
Mon Aug 11 21:08:07 UTC 2025
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?
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
>>>
>>
>
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