Re: [PATCH v2 03/20] drm/mode-config: Mention drm_mode_config_reset() culprits

From: Thomas Zimmermann

Date: Tue Apr 21 2026 - 09:41:13 EST


Hi

Am 21.04.26 um 15:18 schrieb Maxime Ripard:
Hi Thomas,

On Tue, Apr 21, 2026 at 03:08:03PM +0200, Thomas Zimmermann wrote:
Hi

Am 20.03.26 um 17:27 schrieb Maxime Ripard:
drm_mode_config_reset() does not reset drm_private_states by design.

This is especially significant for the DP MST and tunneling code that
expect to be preserved across a suspend/resume cycle, where
drm_mode_config_reset() is also used.
Do we really? There's drm_mode_config_helper_suspend/resume(). Why would
drivers do a drm_mode_config_reset().
drm_mode_config_helper_resume() will call drm_atomic_helper_resume()
that call drm_mode_config_reset(). So (most) drivers will not directly
call it, but it is going to be called still.

I see, thanks. I guess you're right when you say that drm_mode_config_reset() is overloaded. LOL.

Best regards
Thomas



Maxime

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Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
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