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Commit e6e7b48b authored by Daniel Vetter's avatar Daniel Vetter
Browse files

drm: Don't race connector registration 



I was under the misconception that the sysfs dev stuff can be fully
set up, and then registered all in one step with device_add. That's
true for properties and property groups, but not for parents and child
devices. Those must be fully registered before you can register a
child.

Add a bit of tracking to make sure that asynchronous mst connector
hotplugging gets this right. For consistency we rely upon the implicit
barriers of the connector->mutex, which is taken anyway, to ensure
that at least either the connector or device registration call will
work out.

Mildly tested since I can't reliably reproduce this on my mst box
here.

Reported-by: default avatarDave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Acked-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1484237756-2720-1-git-send-email-daniel.vetter@ffwll.ch
parent 4e5b54f1

drivers/gpu/drm/drm_connector.c

+3 −0
Original line number Diff line number Diff line
@@ -379,6 +379,9 @@ int drm_connector_register(struct drm_connector *connector) 
{

	int ret = 0;



	if (!connector->dev->registered)

		return 0;



	mutex_lock(&connector->mutex);

	if (connector->registered)

		goto unlock;

drivers/gpu/drm/drm_drv.c

+4 −0
Original line number Diff line number Diff line
@@ -745,6 +745,8 @@ int drm_dev_register(struct drm_device *dev, unsigned long flags) 
	if (ret)

		goto err_minors;



	dev->registered = true;



	if (dev->driver->load) {

		ret = dev->driver->load(dev, flags);

		if (ret)
@@ -785,6 +787,8 @@ void drm_dev_unregister(struct drm_device *dev) 


	drm_lastclose(dev);



	dev->registered = false;



	if (drm_core_check_feature(dev, DRIVER_MODESET))

		drm_modeset_unregister_all(dev);

include/drm/drmP.h

+1 −0
Original line number Diff line number Diff line
@@ -517,6 +517,7 @@ struct drm_device { 
	struct drm_minor *control;		/**< Control node */

	struct drm_minor *primary;		/**< Primary node */

	struct drm_minor *render;		/**< Render node */

	bool registered;



	/* currently active master for this device. Protected by master_mutex */

	struct drm_master *master;