[PATCH] drm/atomic-helper: Grab connection_mutex while duplicating state
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 > Date: Thu Jul 9 23:44:28 2015 +0200 > > drm: Check locking in drm_for_each_connector > > Cc: Daniel Vetter > Cc: Maarten Lankhorst > Signed-off-by: Matt Roper > --- > 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(>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
[Intel-gfx] [PATCH] drm/atomic-helper: Grab connection_mutex while duplicating state
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 > Date: Thu Jul 9 23:44:28 2015 +0200 > > drm: Check locking in drm_for_each_connector > > Cc: Daniel Vetter > Cc: Maarten Lankhorst > Signed-off-by: Matt Roper 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(>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 at lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/intel-gfx -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch
[PATCH] drm/atomic-helper: Grab connection_mutex while duplicating 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 Date: Thu Jul 9 23:44:28 2015 +0200 drm: Check locking in drm_for_each_connector Cc: Daniel Vetter Cc: Maarten Lankhorst Signed-off-by: Matt Roper --- 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(>mode_config.connection_mutex, ctx); + if (err) + goto free; + drm_for_each_connector(conn, dev) { struct drm_connector_state *conn_state; -- 2.1.4