Instead of scheduling the work to handle the initial delayed event, use 1s delay. This delay should not be needed, but Optimus/nouveau will fail in a mysterious way if the delayed event is handled as soon as possible like it is done in drm_helper_probe_single_connector_modes() in case the poll was enabled before. Reverting 339fd36238dd would give back the 10 sec (!) delay to handle the delayed event. Adding 1sec delay to the poll_work is enough to work around the issue in Optimus setups and gives shorter response on handling the initial delayed event. Fixes: 339fd36238dd ("drm: drm_probe_helper: Fix output_poll_work scheduling") Cc: stable@xxxxxxxxxxxxxxx # v4.9 Signed-off-by: Peter Ujfalusi <peter.ujfalusi@xxxxxx> --- drivers/gpu/drm/drm_probe_helper.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c index 06a62e37fbdc..258abed43e38 100644 --- a/drivers/gpu/drm/drm_probe_helper.c +++ b/drivers/gpu/drm/drm_probe_helper.c @@ -146,8 +146,16 @@ void drm_kms_helper_poll_enable_locked(struct drm_device *dev) drm_connector_list_iter_put(&conn_iter); if (dev->mode_config.delayed_event) { + /* + * Use short (1s) delay to handle the initial delayed event. + * This delay should not be needed, but Optimus/nouveau will + * fail in a mysterious way if the delayed event is handled as + * soon as possible like it is done in + * drm_helper_probe_single_connector_modes() in case the poll + * was enabled before. + */ poll = true; - delay = 0; + delay = HZ; } if (poll) -- 2.11.0 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html