Patch "drm/i915: tune down the fast link training vs boot fail" has been added to the 4.9-stable tree

Patch "drm/i915: tune down the fast link training vs boot fail" has been added to the 4.9-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    drm/i915: tune down the fast link training vs boot fail

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-i915-tune-down-the-fast-link-training-vs-boot-fail.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@vger.kernel.org> know about it.


>From 2c57b18adb93fc070039538f1ce375d3d3e99bbb Mon Sep 17 00:00:00 2001
From: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Tue, 13 Dec 2016 20:54:14 +0100
Subject: drm/i915: tune down the fast link training vs boot fail
MIME-Version: 1.0
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From: Daniel Vetter <daniel.vetter@ffwll.ch>

commit 2c57b18adb93fc070039538f1ce375d3d3e99bbb upstream.

It's been unfixed since a while and no one is immediately working on
this. And we have the FIXME already. And now also a task in the DP
team's backlog.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: stable@vger.kernel.org
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
References: https://lists.freedesktop.org/archives/intel-gfx/2016-July/101951.html
Acked-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
[danvet: Adjust comment per Ville's feedback.]
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161213195414.28923-1-daniel.vetter@ffwll.ch
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

(cherry picked from commit 2dd85aeb5bc99e3763dd192cdb95ff405a102c8a)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

---
 drivers/gpu/drm/i915/intel_dp.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -4019,8 +4019,8 @@ intel_dp_check_link_status(struct intel_
 		return;
 
 	/* FIXME: we need to synchronize this sort of stuff with hardware
-	 * readout */
-	if (WARN_ON_ONCE(!intel_dp->lane_count))
+	 * readout. Currently fast link training doesn't work on boot-up. */
+	if (!intel_dp->lane_count)
 		return;
 
 	/* if link training is requested we should perform it always */


Patches currently in stable-queue which might be from daniel.vetter@ffwll.ch are

queue-4.9/drm-i915-tune-down-the-fast-link-training-vs-boot-fail.patch