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| author | Daniel Vetter <daniel.vetter@ffwll.ch> | 2016-12-18 16:35:45 +0300 |
|---|---|---|
| committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2017-01-30 12:17:17 +0300 |
| commit | 4e5b54f127426c82dc2816340c26d951a5bb3429 (patch) | |
| tree | cc3a8f7e335cf12880bc8d1a1e2066f6cfe0a68e /drivers/gpu | |
| parent | 566cf877a1fcb6d6dc0126b076aad062054c2637 (diff) | |
| download | linux-4e5b54f127426c82dc2816340c26d951a5bb3429.tar.xz | |
drm: prevent double-(un)registration for connectors
If we're unlucky then the registration from a hotplugged connector
might race with the final registration step on driver load. And since
MST topology discover is asynchronous that's even somewhat likely.
v2: Also update the kerneldoc for @registered!
v3: Review from Chris:
- Improve kerneldoc for late_register/early_unregister callbacks.
- Use mutex_destroy.
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Reported-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161218133545.2106-1-daniel.vetter@ffwll.ch
(cherry picked from commit e73ab00e9a0f1731f34d0620a9c55f5c30c4ad4e)
Diffstat (limited to 'drivers/gpu')
| -rw-r--r-- | drivers/gpu/drm/drm_connector.c | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c index 5a4526289392..8be60a4576b3 100644 --- a/drivers/gpu/drm/drm_connector.c +++ b/drivers/gpu/drm/drm_connector.c @@ -225,6 +225,7 @@ int drm_connector_init(struct drm_device *dev, INIT_LIST_HEAD(&connector->probed_modes); INIT_LIST_HEAD(&connector->modes); + mutex_init(&connector->mutex); connector->edid_blob_ptr = NULL; connector->status = connector_status_unknown; @@ -359,6 +360,8 @@ void drm_connector_cleanup(struct drm_connector *connector) connector->funcs->atomic_destroy_state(connector, connector->state); + mutex_destroy(&connector->mutex); + memset(connector, 0, sizeof(*connector)); } EXPORT_SYMBOL(drm_connector_cleanup); @@ -374,14 +377,15 @@ EXPORT_SYMBOL(drm_connector_cleanup); */ int drm_connector_register(struct drm_connector *connector) { - int ret; + int ret = 0; + mutex_lock(&connector->mutex); if (connector->registered) - return 0; + goto unlock; ret = drm_sysfs_connector_add(connector); if (ret) - return ret; + goto unlock; ret = drm_debugfs_connector_add(connector); if (ret) { @@ -397,12 +401,14 @@ int drm_connector_register(struct drm_connector *connector) drm_mode_object_register(connector->dev, &connector->base); connector->registered = true; - return 0; + goto unlock; err_debugfs: drm_debugfs_connector_remove(connector); err_sysfs: drm_sysfs_connector_remove(connector); +unlock: + mutex_unlock(&connector->mutex); return ret; } EXPORT_SYMBOL(drm_connector_register); @@ -415,8 +421,11 @@ EXPORT_SYMBOL(drm_connector_register); */ void drm_connector_unregister(struct drm_connector *connector) { - if (!connector->registered) + mutex_lock(&connector->mutex); + if (!connector->registered) { + mutex_unlock(&connector->mutex); return; + } if (connector->funcs->early_unregister) connector->funcs->early_unregister(connector); @@ -425,6 +434,7 @@ void drm_connector_unregister(struct drm_connector *connector) drm_debugfs_connector_remove(connector); connector->registered = false; + mutex_unlock(&connector->mutex); } EXPORT_SYMBOL(drm_connector_unregister); |