Re: [PATCH 03/14] drm/mode-config: Mention drm_mode_config_reset() culprits
From: Laurent Pinchart
Date: Mon Mar 16 2026 - 12:00:39 EST
On Tue, Mar 10, 2026 at 05:06:55PM +0100, Maxime Ripard wrote:
> drm_mode_config_reset() has the expectation that drm_private_states are
> not reset.
I initially misinterpreted that. I don't think it's an "expectation".
The function simply does not reset the private objects states. If you
want to keep "expectation", you can write
drm_mode_config_reset() has the expectation that drm_private_states do
not need to be reset.
> 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.
>
> Let's document this expectation.
>
> Link: https://lore.kernel.org/dri-devel/aOaQLx-7EpsHRwkH@ideak-desk/
> Signed-off-by: Maxime Ripard <mripard@xxxxxxxxxx>
> ---
> drivers/gpu/drm/drm_mode_config.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_mode_config.c b/drivers/gpu/drm/drm_mode_config.c
> index 84ae8a23a36786705fea7c0eafd7f20813b7c8f9..54c27376f9894ef5eee378bb5b1e5fc7049de922 100644
> --- a/drivers/gpu/drm/drm_mode_config.c
> +++ b/drivers/gpu/drm/drm_mode_config.c
> @@ -187,10 +187,14 @@ int drm_mode_getresources(struct drm_device *dev, void *data,
> * @dev: drm device
> *
> * This functions calls all the crtc's, encoder's and connector's ->reset
> * callback. Drivers can use this in e.g. their driver load or resume code to
> * reset hardware and software state.
> + *
> + * It's worth noting that @drm_private_obj structures are expected to be
s/It's worth noting/Note/
> + * stable across suspend/resume cycles, and @drm_mode_config_reset()
> + * will not affect these structures.
s/will/does/
With this addressed,
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>
> */
> void drm_mode_config_reset(struct drm_device *dev)
> {
> struct drm_crtc *crtc;
> struct drm_colorop *colorop;
>
--
Regards,
Laurent Pinchart