@@ -508,6 +508,8 @@ drm_atomic_helper_check_modeset(struct drm_device *dev,
bool has_connectors =
!!new_crtc_state->connector_mask;
+ WARN_ON(!drm_modeset_is_locked(&crtc->mutex));
+
if (!drm_mode_equal(&old_crtc_state->mode, &new_crtc_state->mode)) {
DRM_DEBUG_ATOMIC("[CRTC:%d:%s] mode changed\n",
crtc->base.id, crtc->name);
@@ -551,6 +553,8 @@ drm_atomic_helper_check_modeset(struct drm_device *dev,
for_each_oldnew_connector_in_state(state, connector, old_connector_state, new_connector_state, i) {
const struct drm_connector_helper_funcs *funcs = connector->helper_private;
+ WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
+
/*
* This only sets crtc->connectors_changed for routing changes,
* drivers must set crtc->connectors_changed themselves when
@@ -650,6 +654,8 @@ drm_atomic_helper_check_planes(struct drm_device *dev,
for_each_oldnew_plane_in_state(state, plane, old_plane_state, new_plane_state, i) {
const struct drm_plane_helper_funcs *funcs;
+ WARN_ON(!drm_modeset_is_locked(&plane->mutex));
+
funcs = plane->helper_private;
drm_atomic_helper_plane_changed(state, old_plane_state, new_plane_state, plane);
@@ -2669,7 +2675,12 @@ int drm_atomic_helper_resume(struct drm_device *dev,
drm_modeset_acquire_init(&ctx, 0);
while (1) {
+ err = drm_modeset_lock_all_ctx(dev, &ctx);
+ if (err)
+ goto out;
+
err = drm_atomic_helper_commit_duplicated_state(state, &ctx);
+out:
if (err != -EDEADLK)
break;
In the conversion to drop drm_modeset_lock_all and the magic implicit context I failed to realize that _resume starts out with a pile of state copies, but not with the locks. And hence drm_atomic_commit won't grab these for us. v2: Add locking checks in helpers to make sure we catch this in the future. Note we can only require the locks in the atomic_check phase, not in the commit phase. But since any commit is guaranteed to first run the checks (even for the resume stuff where we use stored duplicated old state) this should give us full coverage. Requested by Maarten. Cc: Jyri Sarha <jsarha@ti.com> Fixes: a5b8444e289c ("drm/atomic-helper: remove modeset_lock_all from helper_resume") Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Daniel Vetter <daniel.vetter@intel.com> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Sean Paul <seanpaul@chromium.org> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> --- Needs to be applied to drm-misc-fixes for 4.12. Jyri, testing from you would also be great, just to confirm. -Daniel --- drivers/gpu/drm/drm_atomic_helper.c | 11 +++++++++++ 1 file changed, 11 insertions(+)