linux-kernel - [PATCH v2 2/2] drm: bridge: document bridge attach/detach imbalance

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Mon,  6 Aug 2018 08:19:10 +0200
From:   Peter Rosin <peda@...ntia.se>
To:     linux-kernel@...r.kernel.org
Cc:     Peter Rosin <peda@...ntia.se>,
        Gustavo Padovan <gustavo@...ovan.org>,
        Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
        Sean Paul <seanpaul@...omium.org>,
        David Airlie <airlied@...ux.ie>,
        Benjamin Gaignard <benjamin.gaignard@...aro.org>,
        Vincent Abriou <vincent.abriou@...com>,
        dri-devel@...ts.freedesktop.org, Daniel Vetter <daniel@...ll.ch>
Subject: [PATCH v2 2/2] drm: bridge: document bridge attach/detach imbalance

Since 4a878c03d562 ("drm: bridge: Detach bridge from encoder at encoder
cleanup time"), it is generally no longer correct to detach bridges from
encoders manually. Document that.

Signed-off-by: Peter Rosin <peda@...ntia.se>
---
 drivers/gpu/drm/drm_bridge.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c
index 1638bfe9627c..ba7025041e46 100644
--- a/drivers/gpu/drm/drm_bridge.c
+++ b/drivers/gpu/drm/drm_bridge.c
@@ -104,6 +104,10 @@ EXPORT_SYMBOL(drm_bridge_remove);
  * If non-NULL the previous bridge must be already attached by a call to this
  * function.
  *
+ * Note that bridges attached to encoders are auto-detached during encoder
+ * cleanup in drm_encoder_cleanup(), so drm_bridge_attach() should generally
+ * *not* be balanced with a drm_bridge_detach() in driver code.
+ *
  * RETURNS:
  * Zero on success, error code on failure
  */
-- 
2.11.0