This is a note to let you know that I've just added the patch titled drm: Schedule the output_poll_work with 1s delay if we have delayed event to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drm-schedule-the-output_poll_work-with-1s-delay-if-we-have-delayed-event.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 68f458eec7069d618a6c884ca007426e0cea411b Mon Sep 17 00:00:00 2001 From: Peter Ujfalusi <peter.ujfalusi@xxxxxx> Date: Mon, 9 Jan 2017 16:31:58 +0200 Subject: drm: Schedule the output_poll_work with 1s delay if we have delayed event From: Peter Ujfalusi <peter.ujfalusi@xxxxxx> commit 68f458eec7069d618a6c884ca007426e0cea411b upstream. 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") Signed-off-by: Peter Ujfalusi <peter.ujfalusi@xxxxxx> [danvet: Add FIXME to the comment to make it stick out more.] Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxx> Link: http://patchwork.freedesktop.org/patch/msgid/20170109143158.21917-1-peter.ujfalusi@xxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/drm_probe_helper.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) --- a/drivers/gpu/drm/drm_probe_helper.c +++ b/drivers/gpu/drm/drm_probe_helper.c @@ -143,8 +143,18 @@ void drm_kms_helper_poll_enable_locked(s } if (dev->mode_config.delayed_event) { + /* + * FIXME: + * + * 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) Patches currently in stable-queue which might be from peter.ujfalusi@xxxxxx are queue-4.9/drm-schedule-the-output_poll_work-with-1s-delay-if-we-have-delayed-event.patch -- 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