From 7a3f3d6667f5f9ffd1517f6b21d64bbf5312042c Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Thu, 9 Jul 2015 23:44:28 +0200 Subject: [PATCH] drm: Check locking in drm_for_each_connector Because of DP MST connectors can now be hotplugged and we must hold the right lock when walking the connector lists. Enforce this by checking the locking in our shiny new list walking macros. v2: Extract the locking check into a small static inline helper to help readability. This will be more important when we make the read list access rules more complicated in later patches. Inspired by comments from Chris. Unfortunately, due to header loops around the definition of struct drm_device the function interface is a bit funny. v3: Encoders aren't hotadded/removed. For each dp mst encoder we statically create one fake encoder per pipe so that we can support as many mst sinks as the hw can (Dave). Cc: Chris Wilson Cc: Dave Airlie Reviewed-by: Maarten Lankhorst Signed-off-by: Daniel Vetter --- include/drm/drm_crtc.h | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h index 7c95a7df6065..499562274353 100644 --- a/include/drm/drm_crtc.h +++ b/include/drm/drm_crtc.h @@ -1589,8 +1589,18 @@ static inline struct drm_property *drm_property_find(struct drm_device *dev, #define drm_for_each_crtc(crtc, dev) \ list_for_each_entry(crtc, &(dev)->mode_config.crtc_list, head) +static inline void +assert_drm_connector_list_read_locked(struct drm_mode_config *mode_config) +{ + WARN_ON(!mutex_is_locked(&mode_config->mutex)); +} + #define drm_for_each_connector(connector, dev) \ - list_for_each_entry(connector, &(dev)->mode_config.connector_list, head) + for (assert_drm_connector_list_read_locked(&(dev)->mode_config), \ + 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) -- GitLab