Commit 326fdffd authored by Daniel Vetter's avatar Daniel Vetter Committed by Greg Kroah-Hartman

drm: Don't race connector registration


[ Upstream commit e6e7b48b ]

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.chSigned-off-by: default avatarSasha Levin <alexander.levin@verizon.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 82b6693b
......@@ -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;
......
......@@ -710,6 +710,8 @@ 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)
......@@ -749,6 +751,8 @@ 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);
......
......@@ -776,6 +776,7 @@ 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;
......
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