This is a note to let you know that I've just added the patch titled
drm/i915: Skip load detect when intel_crtc->new_enable==true
to the 3.16-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-skip-load-detect-when-intel_crtc-new_enable-true.patch
and it can be found in the queue-3.16 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From a459249c73eaec1daf4e4657ea3564cc3550e66c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= <ville.syrjala@xxxxxxxxxxxxxxx>
Date: Mon, 11 Aug 2014 13:15:36 +0300
Subject: drm/i915: Skip load detect when intel_crtc->new_enable==true
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From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= <ville.syrjala@xxxxxxxxxxxxxxx>
commit a459249c73eaec1daf4e4657ea3564cc3550e66c upstream.
During suspend we turn off the crtcs, but leave the staged config in
place so that we can restore the display(s) to their previous state on
resume.
During resume when we attempt to apply the force pipe A quirk we use the
load detect mechanism. That doesn't check whether there was an already
staged configuration for the crtc since that's not even possible during
normal runtime load detection. But during resume it is possible, and if
we just blindly go and overwrite the staged crtc configuration for the
load detection we can no longer restore the display to the correct
state.
Even worse, we don't even clear all the staged connector->encoder->crtc
links so we may end up using a cloned setup for the load detection, and
after we're done we just clear the links related to the VGA output
leaving the links for the other outputs in place. This will eventually
result in calling intel_set_mode() with mode==NULL but with valid
connector->encoder->crtc links which will result in dereferencing the
NULL mode since the code thinks it will have to a modeset.
To avoid these problems don't use any crtc with new_enabled==true for
load detection.
Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/intel_display.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -8359,10 +8359,14 @@ retry:
i++;
if (!(encoder->possible_crtcs & (1 << i)))
continue;
- if (!possible_crtc->enabled) {
- crtc = possible_crtc;
- break;
- }
+ if (possible_crtc->enabled)
+ continue;
+ /* This can occur when applying the pipe A quirk on resume. */
+ if (to_intel_crtc(possible_crtc)->new_enabled)
+ continue;
+
+ crtc = possible_crtc;
+ break;
}
/*
Patches currently in stable-queue which might be from ville.syrjala@xxxxxxxxxxxxxxx are
queue-3.16/drm-i915-skip-load-detect-when-intel_crtc-new_enable-true.patch
queue-3.16/drm-i915-wait-for-vblank-before-enabling-the-tv-encoder.patch
queue-3.16/drm-i915-fix-lock-dropping-in-intel_tv_detect.patch
queue-3.16/drm-i915-don-t-try-to-retrain-a-dp-link-on-an-inactive-crtc.patch
queue-3.16/drm-i915-fix-locking-for-intel_enable_pipe_a.patch
queue-3.16/drm-i915-fix-plane-cursor-handling-when-runtime-suspended.patch
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