[PATCH 05/11] drm: Check locking in drm_for_each_encoder/connector

Daniel Vetter daniel.vetter at ffwll.ch
Tue Jun 23 13:45:56 PDT 2015


Because of DP MST encoders/connectors can now be hotplugged and we
must hold the right lock when walking the encoder/connector lists.
Enforce this by checking the locking in our shiny new list walking
macros.

Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
---
 include/drm/drm_crtc.h | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index 5994750f523a..a912ba06cf45 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -1588,10 +1588,18 @@ static inline struct drm_property *drm_property_find(struct drm_device *dev,
 	list_for_each_entry(crtc, &(dev)->mode_config.crtc_list, head)
 
 #define drm_for_each_connector(connector, dev) \
-	list_for_each_entry(connector, &(dev)->mode_config.connector_list, head)
+	for (WARN_ON(!mutex_is_locked(&(dev)->mode_config.mutex)),		\
+	     connector = list_first_entry(&(dev)->mode_config.connector_list,	\
+					  struct drm_connector, head);		\
+	     &connector->head != (&(dev)->mode_config.connector_list);		\
+	     connector = list_next_entry(connector, head))
 
 #define drm_for_each_encoder(encoder, dev) \
-	list_for_each_entry(encoder, &(dev)->mode_config.encoder_list, head)
+	for (WARN_ON(!mutex_is_locked(&(dev)->mode_config.mutex)),		\
+	     encoder = list_first_entry(&(dev)->mode_config.encoder_list,	\
+					  struct drm_encoder, head);		\
+	     &encoder->head != (&(dev)->mode_config.encoder_list);		\
+	     encoder = list_next_entry(encoder, head))
 
 #define drm_for_each_fb(fb, dev) \
 	list_for_each_entry(fb, &(dev)->mode_config.fb_list, head)
-- 
2.1.4



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