[PATCH v2 2/3] drm/dp_helper: Mention the concurrency requirement hw_mutex

[Maxime Ripard]

Drivers that allow concurrent access over multiple DP channels need to
provide additional locking, even though the hw_mutex field might
indicate otherwise. Clarify it in the documentation.

Suggested-by: Daniel Vetter <daniel.vetter at ffwll.ch>
Signed-off-by: Maxime Ripard <maxime at cerno.tech>

---

Changes from v1:
  - New patch
---
 include/drm/drm_dp_helper.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index 1c5ae07ff0c7..0cc6062ff3ad 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -1878,6 +1878,10 @@ struct drm_dp_aux {
 
 	/**
 	 * @hw_mutex: internal mutex used for locking transfers.
+	 *
+	 * Note that if the underlying hardware is shared among multiple
+	 * channels, the driver needs to do additional locking to
+	 * prevent concurrent access.
 	 */
 	struct mutex hw_mutex;
 
-- 
2.31.1