FAILED: patch "[PATCH] drm/i915: tune down the fast link training vs boot fail" failed to apply to 4.9-stable tree

FAILED: patch "[PATCH] drm/i915: tune down the fast link training vs boot fail" failed to apply to 4.9-stable tree

[gregkh]

The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

>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: [PATCH] drm/i915: tune down the fast link training vs boot fail
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

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

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

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 90283edcafba..d9bc19be855e 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -4014,8 +4014,8 @@ intel_dp_check_link_status(struct intel_dp *intel_dp)
 		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 */

Re: FAILED: patch "[PATCH] drm/i915: tune down the fast link training vs boot fail" failed to apply to 4.9-stable tree

[koos vriezen]

Hi,

Looks like "[PATCH] drm/i915: tune down the fast link training vs boot
fail" is based on
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/drivers/gpu/drm/i915/intel_dp.c?id=d4cb3fd9b548b8bfe2a712ec920b9ebabd3547ab

Combined I get this diff

--- a/drivers/gpu/drm/i915/intel_dp.c        2017-01-08 14:37:01.443536926 +0100
+++ b/drivers/gpu/drm/i915/intel_dp.c      2017-01-08 14:37:17.703138505 +0100
@@ -4017,6 +4017,11 @@
        if (!to_intel_crtc(intel_encoder->base.crtc)->active)
                return;

+       /* FIXME: we need to synchronize this sort of stuff with hardware
+        * 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 */
        if ((intel_dp->compliance_test_type == DP_TEST_LINK_TRAINING) ||
            (!drm_dp_channel_eq_ok(link_status, intel_dp->lane_count))) {


Regards,
Koos

Re: FAILED: patch "[PATCH] drm/i915: tune down the fast link training vs boot fail" failed to apply to 4.9-stable tree

[Greg KH]

On Sun, Jan 08, 2017 at 02:40:57PM +0100, koos vriezen wrote:
> Hi,
> 
> Looks like "[PATCH] drm/i915: tune down the fast link training vs boot
> fail" is based on
> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/drivers/gpu/drm/i915/intel_dp.c?id=d4cb3fd9b548b8bfe2a712ec920b9ebabd3547ab
> 
> Combined I get this diff
> 
> --- a/drivers/gpu/drm/i915/intel_dp.c        2017-01-08 14:37:01.443536926 +0100
> +++ b/drivers/gpu/drm/i915/intel_dp.c      2017-01-08 14:37:17.703138505 +0100
> @@ -4017,6 +4017,11 @@
>         if (!to_intel_crtc(intel_encoder->base.crtc)->active)
>                 return;
> 
> +       /* FIXME: we need to synchronize this sort of stuff with hardware
> +        * 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 */
>         if ((intel_dp->compliance_test_type == DP_TEST_LINK_TRAINING) ||
>             (!drm_dp_channel_eq_ok(link_status, intel_dp->lane_count))) {
> 
> 

What does that mean, I should include the previous patch as well?
Please be specific, I have no short-term memory :)

greg k-h

Re: FAILED: patch "[PATCH] drm/i915: tune down the fast link training vs boot fail" failed to apply to 4.9-stable tree

[koos vriezen]

Hi,

2017-01-08 15:50 GMT+01:00 Greg KH <greg@kroah.com>:
> On Sun, Jan 08, 2017 at 02:40:57PM +0100, koos vriezen wrote:
>> Hi,
>>
>> Looks like "[PATCH] drm/i915: tune down the fast link training vs boot
>> fail" is based on
>> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/drivers/gpu/drm/i915/intel_dp.c?id=d4cb3fd9b548b8bfe2a712ec920b9ebabd3547ab
>>
>> Combined I get this diff
>>
>> --- a/drivers/gpu/drm/i915/intel_dp.c        2017-01-08 14:37:01.443536926 +0100
>> +++ b/drivers/gpu/drm/i915/intel_dp.c      2017-01-08 14:37:17.703138505 +0100
>> @@ -4017,6 +4017,11 @@
>>         if (!to_intel_crtc(intel_encoder->base.crtc)->active)
>>                 return;
>>
>> +       /* FIXME: we need to synchronize this sort of stuff with hardware
>> +        * 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 */
>>         if ((intel_dp->compliance_test_type == DP_TEST_LINK_TRAINING) ||
>>             (!drm_dp_channel_eq_ok(link_status, intel_dp->lane_count))) {
>>
>>
>
> What does that mean, I should include the previous patch as well?
> Please be specific, I have no short-term memory :)

Just compiled with both patches and see no problem. Judging the
d4cb3fd9b548b8bfe2a712ec920b9ebabd3547ab commit description and commit
date, I think yes. Added Ville Syrjälä to judge whether stable should
have that patch.

Koos

> greg k-h

Re: FAILED: patch "[PATCH] drm/i915: tune down the fast link training vs boot fail" failed to apply to 4.9-stable tree

[Greg KH]

On Mon, Jan 09, 2017 at 12:25:44PM +0100, koos vriezen wrote:
> Hi,
> 
> 2017-01-08 15:50 GMT+01:00 Greg KH <greg@kroah.com>:
> > On Sun, Jan 08, 2017 at 02:40:57PM +0100, koos vriezen wrote:
> >> Hi,
> >>
> >> Looks like "[PATCH] drm/i915: tune down the fast link training vs boot
> >> fail" is based on
> >> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/drivers/gpu/drm/i915/intel_dp.c?id=d4cb3fd9b548b8bfe2a712ec920b9ebabd3547ab
> >>
> >> Combined I get this diff
> >>
> >> --- a/drivers/gpu/drm/i915/intel_dp.c        2017-01-08 14:37:01.443536926 +0100
> >> +++ b/drivers/gpu/drm/i915/intel_dp.c      2017-01-08 14:37:17.703138505 +0100
> >> @@ -4017,6 +4017,11 @@
> >>         if (!to_intel_crtc(intel_encoder->base.crtc)->active)
> >>                 return;
> >>
> >> +       /* FIXME: we need to synchronize this sort of stuff with hardware
> >> +        * 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 */
> >>         if ((intel_dp->compliance_test_type == DP_TEST_LINK_TRAINING) ||
> >>             (!drm_dp_channel_eq_ok(link_status, intel_dp->lane_count))) {
> >>
> >>
> >
> > What does that mean, I should include the previous patch as well?
> > Please be specific, I have no short-term memory :)
> 
> Just compiled with both patches and see no problem. Judging the
> d4cb3fd9b548b8bfe2a712ec920b9ebabd3547ab commit description and commit
> date, I think yes. Added Ville Syrj�l� to judge whether stable should
> have that patch.

Ok, that looks good, I've queued up both of these patches now, thanks
for the help, much appreciated.

greg k-h