[PATCH v5 00/14] drm/amd/display: more drm_edid to AMD display driver
Alex Hung
alex.hung at amd.com
Fri Jul 11 15:54:00 UTC 2025
Thanks Melissa. I will send this series to promotion test and post the
result by the end of next week.
On 6/18/25 11:19, 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.
>
> In short, this series approaches the issue of maintaining DC as an
> OS-agnostic component by creating a mid layer to isolate `drm_edid`
> helpers that need to be called in the DC code, while allowing other OSes
> to implement their specific implementation. This is an extension of [1].
>
> - Patch 1 addresses a possible leak added by previous migration t drm/amd/display: more drm_edid to AMD display driver
o
> 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
>
> ---
>
> 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.
>
> Finally, I'm not sure amdgpu_dm/dc_edid is the right place and file name
> for the mid-layer. Suggestions?
>
> [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 | 105 +++++++-----------
> .../display/amdgpu_dm/amdgpu_dm_mst_types.c | 21 ++--
> .../gpu/drm/amd/display/amdgpu_dm/dc_edid.c | 33 ++++++
> .../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, 193 insertions(+), 160 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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