diff options
| author | Daniel Vetter <daniel.vetter@ffwll.ch> | 2016-12-18 16:35:45 +0300 |
|---|---|---|
| committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2016-12-18 16:36:18 +0300 |
| commit | e73ab00e9a0f1731f34d0620a9c55f5c30c4ad4e (patch) | |
| tree | c82bd3206afa2bec041408d5074628fae30a642c /include | |
| parent | 2ab8c5f8c0358010a19e82656fa4826a6a51d1e0 (diff) | |
| download | linux-e73ab00e9a0f1731f34d0620a9c55f5c30c4ad4e.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
Diffstat (limited to 'include')
| -rw-r--r-- | include/drm/drm_connector.h | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h index 0e41a2e184a9..e4f23cc2aaab 100644 --- a/include/drm/drm_connector.h +++ b/include/drm/drm_connector.h @@ -381,6 +381,8 @@ struct drm_connector_funcs { * core drm connector interfaces. Everything added from this callback * should be unregistered in the early_unregister callback. * + * This is called while holding drm_connector->mutex. + * * Returns: * * 0 on success, or a negative error code on failure. @@ -395,6 +397,8 @@ struct drm_connector_funcs { * late_register(). It is called from drm_connector_unregister(), * early in the driver unload sequence to disable userspace access * before data structures are torndown. + * + * This is called while holding drm_connector->mutex. */ void (*early_unregister)(struct drm_connector *connector); @@ -559,7 +563,6 @@ struct drm_cmdline_mode { * @interlace_allowed: can this connector handle interlaced modes? * @doublescan_allowed: can this connector handle doublescan? * @stereo_allowed: can this connector handle stereo modes? - * @registered: is this connector exposed (registered) with userspace? * @modes: modes available on this connector (from fill_modes() + user) * @status: one of the drm_connector_status enums (connected, not, or unknown) * @probed_modes: list of modes derived directly from the display @@ -608,6 +611,13 @@ struct drm_connector { char *name; /** + * @mutex: Lock for general connector state, but currently only protects + * @registered. Most of the connector state is still protected by the + * mutex in &drm_mode_config. + */ + struct mutex mutex; + + /** * @index: Compacted connector index, which matches the position inside * the mode_config.list for drivers not supporting hot-add/removing. Can * be used as an array index. It is invariant over the lifetime of the @@ -620,6 +630,10 @@ struct drm_connector { bool interlace_allowed; bool doublescan_allowed; bool stereo_allowed; + /** + * @registered: Is this connector exposed (registered) with userspace? + * Protected by @mutex. + */ bool registered; struct list_head modes; /* list of modes on this connector */ |