[PATCH v4 05/20] drm/mode-config: Document drm_private_obj exclusion from drm_mode_config_reset()

[Maxime Ripard <mripard@kernel.org>]

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.

Document this expectation.

Link: https://lore.kernel.org/dri-devel/aOaQLx-7EpsHRwkH@ideak-desk/
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
---
 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 66f7dc37b597..c33382a38191 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.
+ *
+ * Note that &drm_private_obj structures are expected to be stable across
+ * suspend/resume cycles, and drm_mode_config_reset() does not affect these
+ * structures.
  */
 void drm_mode_config_reset(struct drm_device *dev)
 {
 	struct drm_crtc *crtc;
 	struct drm_colorop *colorop;

-- 
2.54.0