diff options
| author | Daniel Vetter <daniel.vetter@ffwll.ch> | 2016-12-18 14:35:45 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-06-17 06:41:53 +0200 |
| commit | 82b6693bd4153dc437255dabaa4f9d0d0f8c9da2 (patch) | |
| tree | 87f4562db2d38f58c197a974dbd4f493a45e19f3 /include | |
| parent | d934fe02ba176b5e88d8b67d603cd94fc930f3ce (diff) | |
drm: prevent double-(un)registration for connectors
[ Upstream commit e73ab00e9a0f1731f34d0620a9c55f5c30c4ad4e ]
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
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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 ac9d7d8e0e43..d8bb8d151825 100644 --- a/include/drm/drm_connector.h +++ b/include/drm/drm_connector.h @@ -345,6 +345,8 @@ 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. @@ -359,6 +361,8 @@ 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); @@ -511,7 +515,6 @@ 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 @@ -560,6 +563,13 @@ 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 @@ -572,6 +582,10 @@ 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 */ |