| Message ID | 1448925769-12324-1-git-send-email-matthew.d.roper@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Nov 30, 2015 at 03:22:49PM -0800, Matt Roper wrote: > Callers of drm_atomic_helper_duplicate_state() may not have grabbed > locks before calling this function. We're not supposed to iterate over > connectors without holding connection_mutex (since MST allows new > connectors to be spawned at hotplug), so make sure we grab that > ourselves before invoking drm_for_each_connector(). Failure to grab > this lock would cause us to stumble over the assertion added in commit: > > commit 7a3f3d6667f5f9ffd1517f6b21d64bbf5312042c > Author: Daniel Vetter <daniel.vetter@ffwll.ch> > Date: Thu Jul 9 23:44:28 2015 +0200 > > drm: Check locking in drm_for_each_connector > > Cc: Daniel Vetter <daniel.vetter@ffwll.ch> > Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> > Signed-off-by: Matt Roper <matthew.d.roper@intel.com> These helpers are wip and Thierry is working on some additional higher-level wrappers for bullet proof save/restore for atomic drivers. It's very much intentinoal that this function here does _not_ grab any locks - if it does the higher-level magic would be impossible. -Daniel > --- > drivers/gpu/drm/drm_atomic_helper.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c > index 3731a26..e5d0b21 100644 > --- a/drivers/gpu/drm/drm_atomic_helper.c > +++ b/drivers/gpu/drm/drm_atomic_helper.c > @@ -2478,6 +2478,10 @@ drm_atomic_helper_duplicate_state(struct drm_device *dev, > } > } > > + err = drm_modeset_lock(&dev->mode_config.connection_mutex, ctx); > + if (err) > + goto free; > + > drm_for_each_connector(conn, dev) { > struct drm_connector_state *conn_state; > > -- > 2.1.4 > > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/intel-gfx
Op 01-12-15 om 00:22 schreef Matt Roper: > Callers of drm_atomic_helper_duplicate_state() may not have grabbed > locks before calling this function. We're not supposed to iterate over > connectors without holding connection_mutex (since MST allows new > connectors to be spawned at hotplug), so make sure we grab that > ourselves before invoking drm_for_each_connector(). Failure to grab > this lock would cause us to stumble over the assertion added in commit: > > commit 7a3f3d6667f5f9ffd1517f6b21d64bbf5312042c > Author: Daniel Vetter <daniel.vetter@ffwll.ch> > Date: Thu Jul 9 23:44:28 2015 +0200 > > drm: Check locking in drm_for_each_connector > > Cc: Daniel Vetter <daniel.vetter@ffwll.ch> > Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> > Signed-off-by: Matt Roper <matthew.d.roper@intel.com> > --- > drivers/gpu/drm/drm_atomic_helper.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c > index 3731a26..e5d0b21 100644 > --- a/drivers/gpu/drm/drm_atomic_helper.c > +++ b/drivers/gpu/drm/drm_atomic_helper.c > @@ -2478,6 +2478,10 @@ drm_atomic_helper_duplicate_state(struct drm_device *dev, > } > } > > + err = drm_modeset_lock(&dev->mode_config.connection_mutex, ctx); > + if (err) > + goto free; > + > drm_for_each_connector(conn, dev) { > struct drm_connector_state *conn_state; > Thanks, that's a lot better than just a random hunk without explanation. Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c index 3731a26..e5d0b21 100644 --- a/drivers/gpu/drm/drm_atomic_helper.c +++ b/drivers/gpu/drm/drm_atomic_helper.c @@ -2478,6 +2478,10 @@ drm_atomic_helper_duplicate_state(struct drm_device *dev, } } + err = drm_modeset_lock(&dev->mode_config.connection_mutex, ctx); + if (err) + goto free; + drm_for_each_connector(conn, dev) { struct drm_connector_state *conn_state;
Callers of drm_atomic_helper_duplicate_state() may not have grabbed locks before calling this function. We're not supposed to iterate over connectors without holding connection_mutex (since MST allows new connectors to be spawned at hotplug), so make sure we grab that ourselves before invoking drm_for_each_connector(). Failure to grab this lock would cause us to stumble over the assertion added in commit: commit 7a3f3d6667f5f9ffd1517f6b21d64bbf5312042c Author: Daniel Vetter <daniel.vetter@ffwll.ch> Date: Thu Jul 9 23:44:28 2015 +0200 drm: Check locking in drm_for_each_connector Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Signed-off-by: Matt Roper <matthew.d.roper@intel.com> --- drivers/gpu/drm/drm_atomic_helper.c | 4 ++++ 1 file changed, 4 insertions(+)