Re: [Intel-gfx] [PATCH 0/4] drm/amd/display: stop using drm_edid_override_connector_update()

[Jani Nikula <jani.nikula@intel.com>]

On Wed, 23 Aug 2023, Jani Nikula <jani.nikula@intel.com> wrote:
> On Tue, 22 Aug 2023, Alex Hung <alex.hung@amd.com> wrote:
>> On 2023-08-22 06:01, Jani Nikula wrote:
>>> Over the past years I've been trying to unify the override and firmware
>>> EDID handling as well as EDID property updates. It won't work if drivers
>>> do their own random things.
>> Let's check how to replace these references by appropriate ones or fork 
>> the function as reverting these patches causes regressions.
>
> I think the fundamental problem you have is conflating connector forcing
> with EDID override. They're orthogonal. The .force callback has no
> business basing the decisions on connector->edid_override. Force is
> force, override is override.
>
> The driver isn't even supposed to know or care if the EDID originates
> from the firmware loader or override EDID debugfs. drm_get_edid() will
> handle that for you transparently. It'll return the EDID, and you
> shouldn't look at connector->edid_blob_ptr either. Using that will make
> future work in drm_edid.c harder.
>
> You can't fix that with minor tweaks. I think you'll be better off
> starting from scratch.
>
> Also, connector->edid_override is debugfs. You actually can change the
> behaviour. If your userspace, whatever it is, has been written to assume
> connector forcing if EDID override is set, you *do* have to fix that,
> and set both.

Any updates on fixing this, or shall we proceed with the reverts?

BR,
Jani.



>
> BR,
> Jani.
>
>
>>
>> Cheers,
>> Alex
>>
>>> 
>>> BR,
>>> Jani.
>>> 
>>> 
>>> Cc: Alex Deucher <alexander.deucher@amd.com>
>>> Cc: Alex Hung <alex.hung@amd.com>
>>> Cc: Chao-kai Wang <Stylon.Wang@amd.com>
>>> Cc: Daniel Wheeler <daniel.wheeler@amd.com>
>>> Cc: Harry Wentland <harry.wentland@amd.com>
>>> Cc: Hersen Wu <hersenxs.wu@amd.com>
>>> Cc: Leo Li <sunpeng.li@amd.com>
>>> Cc: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
>>> Cc: Wenchieh Chien <wenchieh.chien@amd.com>
>>> Cc: David Airlie <airlied@gmail.com>
>>> Cc: Daniel Vetter <daniel@ffwll.ch>
>>> 
>>> Jani Nikula (4):
>>>    Revert "drm/amd/display: drop unused count variable in
>>>      create_eml_sink()"
>>>    Revert "drm/amd/display: assign edid_blob_ptr with edid from debugfs"
>>>    Revert "drm/amd/display: mark amdgpu_dm_connector_funcs_force static"
>>>    Revert "drm/amd/display: implement force function in
>>>      amdgpu_dm_connector_funcs"
>>> 
>>>   .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 44 +++----------------
>>>   1 file changed, 5 insertions(+), 39 deletions(-)
>>> 

-- 
Jani Nikula, Intel Open Source Graphics Center