[PATCH] drm/atomic-helper: Add a note in drm_atomic_helper_reset_crtc() kernel-doc

[Herve Codina <herve.codina@bootlin.com>]

As suggested in [0], add a note indicating that
drm_atomic_helper_reset_crtc() can be a no-op in some cases.

[0]:https://lore.kernel.org/all/Z7XfnPGDYspwG42y@phenom.ffwll.local/

Signed-off-by: Herve Codina <herve.codina@bootlin.com>
---
 This patch applies on top of the following commit available in drm-misc
   ab83b7f6a0c1 ("drm/atomic-helper: Introduce drm_atomic_helper_reset_crtc()")

 drivers/gpu/drm/drm_atomic_helper.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index 0a636c398578..1f93b0a855de 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -3371,6 +3371,10 @@ EXPORT_SYMBOL(drm_atomic_helper_disable_all);
  * This implies a reset of all active components available between the CRTC and
  * connectors.
  *
+ * NOTE: This relies on resetting &drm_crtc_state.connectors_changed.
+ * For drivers which optimize out unnecessary modesets this will result in
+ * a no-op commit, achieving nothing.
+ *
  * Returns:
  * 0 on success or a negative error code on failure.
  */
-- 
2.48.1