Re: [PATCH] drm/amd/display: use atomic commit for panel power savings

[Shivam Kalra]

On 06/11/26 03:15, Alex Hung wrote:
> On 10/30/26 15:58, Shivam Kalra via B4 Relay wrote:
>
> Hi Shivam,
>
> Thanks for the patch. Moving this to an atomic commit is the right direction, but as it stands every write still ends in a full modeset.
>
> In amdgpu_dm_atomic_check(), any abm_level difference between the old and new connector state sets new_crtc_state->connectors_changed = true. That makes drm_atomic_crtc_needs_modeset() true, and commit_tail skips the abm_changed / stream_update.abm_level fast path. Users would see a blank/flicker on the eDP panel on every power-profile change.
>
> Could you try keeping drm_atomic_get_crtc_state() and setting connectors_changed only for scaling? ABM would then go through the existing stream update with no modeset, like David's [PATCH 2/2] drm/amd/display: Avoid modeset for ABM changes - https://lore.kernel.org/amd-gfx/20260813112634.11455-3-weber.aulendorf@xxxxxxxxx/
>
> Please run IGT amd_abm, including abm_gradual, before v2.
>
> Also see inline comments.
Thanks for review! I will send out v2 shortly.