Commit 7a3f3d66 authored Jul 09, 2015 by Daniel Vetter

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 <chris@chris-wilson.co.uk>
Cc: Dave Airlie <airlied@redhat.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>

parent 169faeca

include/drm/drm_crtc.h

+11 −1

Original line number	Diff line number	Diff line
		@@ -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)

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