diff options
| -rw-r--r-- | drivers/gpu/drm/drm_probe_helper.c | 20 | ||||
| -rw-r--r-- | include/drm/drm_crtc_helper.h | 1 |
2 files changed, 21 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c index 6dc2dde5b672..7a6b2dc08913 100644 --- a/drivers/gpu/drm/drm_probe_helper.c +++ b/drivers/gpu/drm/drm_probe_helper.c @@ -655,6 +655,26 @@ out: } /** + * drm_kms_helper_is_poll_worker - is %current task an output poll worker? + * + * Determine if %current task is an output poll worker. This can be used + * to select distinct code paths for output polling versus other contexts. + * + * One use case is to avoid a deadlock between the output poll worker and + * the autosuspend worker wherein the latter waits for polling to finish + * upon calling drm_kms_helper_poll_disable(), while the former waits for + * runtime suspend to finish upon calling pm_runtime_get_sync() in a + * connector ->detect hook. + */ +bool drm_kms_helper_is_poll_worker(void) +{ + struct work_struct *work = current_work(); + + return work && work->func == output_poll_execute; +} +EXPORT_SYMBOL(drm_kms_helper_is_poll_worker); + +/** * drm_kms_helper_poll_disable - disable output polling * @dev: drm_device * diff --git a/include/drm/drm_crtc_helper.h b/include/drm/drm_crtc_helper.h index 76e237bd989b..6914633037a5 100644 --- a/include/drm/drm_crtc_helper.h +++ b/include/drm/drm_crtc_helper.h @@ -77,5 +77,6 @@ void drm_kms_helper_hotplug_event(struct drm_device *dev); void drm_kms_helper_poll_disable(struct drm_device *dev); void drm_kms_helper_poll_enable(struct drm_device *dev); +bool drm_kms_helper_is_poll_worker(void); #endif |