diff options
Diffstat (limited to 'drivers/gpu/drm/drm_probe_helper.c')
| -rw-r--r-- | drivers/gpu/drm/drm_probe_helper.c | 23 |
1 files changed, 21 insertions, 2 deletions
diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c index 6dc2dde5b672..00b8445ba819 100644 --- a/drivers/gpu/drm/drm_probe_helper.c +++ b/drivers/gpu/drm/drm_probe_helper.c @@ -216,8 +216,7 @@ enum drm_mode_status drm_connector_mode_valid(struct drm_connector *connector, * suspend/resume. * * Drivers can call this helper from their device resume implementation. It is - * an error to call this when the output polling support has not yet been set - * up. + * not an error to call this even when output polling isn't enabled. * * Note that calls to enable and disable polling must be strictly ordered, which * is automatically the case when they're only call from suspend/resume @@ -655,6 +654,26 @@ 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 * |