linux-kernel - [PATCH v2] drm: Schedule the output_poll_work with 1s delay if we have delayed event

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20170109143158.21917-1-peter.ujfalusi@ti.com>
Date:   Mon, 9 Jan 2017 16:31:58 +0200
From:   Peter Ujfalusi <peter.ujfalusi@...com>
To:     <daniel.vetter@...el.com>, <jani.nikula@...ux.intel.com>,
        <seanpaul@...omium.org>, <airlied@...ux.ie>
CC:     <dri-devel@...ts.freedesktop.org>, <linux-kernel@...r.kernel.org>,
        <freedesktop-bugs@...lSD.com>, <gleb@...tmail.com>,
        <stable@...r.kernel.org>
Subject: [PATCH v2] drm: Schedule the output_poll_work with 1s delay if we have delayed event

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@...r.kernel.org   # v4.9
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@...com>
---
 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