Bug 73705 - External display not working - failed to enable link training, failed to start channel equalization
Summary: External display not working - failed to enable link training, failed to star...
Status: CLOSED FIXED
Alias: None
Product: DRI
Classification: Unclassified
Component: DRM/Intel (show other bugs)
Version: XOrg git
Hardware: x86-64 (AMD64) Linux (All)
: medium normal
Assignee: Jani Nikula
QA Contact: Intel GFX Bugs mailing list
URL:
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2014-01-16 16:15 UTC by Krzysiek Bielicki
Modified: 2016-09-28 13:22 UTC (History)
2 users (show)

See Also:
i915 platform:
i915 features:

Attachments
dmesg of fully initialized system with x running (up to Gnome-session) (190.30 KB, text/plain)
2014-02-14 07:07 UTC, Krzysiek Bielicki 		no flags Details
After connecting DVI display screen goes black, after disconnecting shows back properly (197.81 KB, text/plain)
2014-02-14 07:08 UTC, Krzysiek Bielicki 		no flags Details
After connecting VGA display screen goes black, after disconnecting shows back properly (204.57 KB, text/plain)
2014-02-14 07:09 UTC, Krzysiek Bielicki 		no flags Details
View All

Description Krzysiek Bielicki 2014-01-16 16:15:59 UTC 
On DELL LATTITUDE E5540,
kernel-3.13.0-rc8
xorg-server-1.15
xf86-video-intel-2.99.907-r1

Boot hangs when KMS with external display connected (DVI-D/VGA to docking station or VGA with docking station disconnected).

It boots completely fine when display is disconnected.
If I connect display with X started (in vt7 console) desktop hangs, I cannot switch to different console.
If I connect display after starting X and switching to text console it works until I switch to X console (vt7).

Few seconds after disconnecting console everything starts working correctly.

In dmesg it prints only:

[  158.165329] [drm:intel_dp_start_link_train] *ERROR* failed to enable link training
[  158.168028] [drm:intel_dp_complete_link_train] *ERROR* failed to start channel equalization
Comment 1 Chris Wilson 2014-01-16 16:20:16 UTC 
I would like to see a perf profile of when X freezes, and/or cat /proc/`pidof X`/stack
Comment 2 Jani Nikula 2014-01-17 14:24:25 UTC 
And a complete dmesg with drm.debug=0xe module parameter is always nice to have.
Comment 3 andreas.sturmlechner 2014-01-25 00:15:04 UTC 
I can see the same dmesg output when (un-)plugging DisplayPort cable from X200s (GM45 chipset) docking station a few times - no hangs though:

[  178.049984] [drm:intel_dp_start_link_train] *ERROR* failed to enable link training
[  178.052592] [drm:intel_dp_complete_link_train] *ERROR* failed to start channel equalization
[  194.914411] [drm:intel_dp_start_link_train] *ERROR* too many voltage retries, give up
Comment 4 Krzysiek Bielicki 2014-02-14 07:07:40 UTC 
Created attachment 94042 [details]
dmesg of fully initialized system with x running (up to Gnome-session)
Comment 5 Krzysiek Bielicki 2014-02-14 07:08:24 UTC 
Created attachment 94043 [details]
After connecting DVI display screen goes black, after disconnecting shows back properly
Comment 6 Krzysiek Bielicki 2014-02-14 07:09:21 UTC 
Created attachment 94044 [details]
After connecting VGA display screen goes black, after disconnecting shows back properly
Comment 7 Krzysiek Bielicki 2014-02-14 10:14:04 UTC 
Linux 3.13.2 #1 SMP Fri Feb 7 13:28:49 CET 2014 x86_64 Intel(R) Core(TM) i5-4300U CPU @ 1.90GHz GenuineIntel GNU/Linux

x11-base/xorg-server-1.15.0
x11-drivers/xf86-video-intel-2.99.910
Comment 8 Krzysiek Bielicki 2014-02-27 10:27:34 UTC 
Is any more info needed??
Comment 9 Krzysiek Bielicki 2014-03-13 09:25:04 UTC 
I don't know if I should make new bug.

DisplayPort (from docking station) also des not work.

dmesg:
[10131.377840] [drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 67
[10131.377850] Raw EDID:
[10131.377856]  	00 ff ff ff ff ff ff 00 10 ac 7a a0 53 4b 47 31
[10131.377861]  	2c 17 01 03 80 00 ff ff ff ff ff ff ff ff ff ff
[10131.377865]  	ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[10131.377869]  	ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[10131.377873]  	ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[10131.377878]  	ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[10131.377882]  	ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[10131.377886]  	ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
[10152.775550] [drm:intel_dp_start_link_train] *ERROR* failed to enable link training
[10152.778327] [drm:intel_dp_complete_link_train] *ERROR* failed to start channel equalization
Comment 10 andreas.sturmlechner 2014-03-13 10:26:58 UTC 
(In reply to comment #9)
> I don't know if I should make new bug.
>
> DisplayPort (from docking station) also des not work.

Same as in my message from above (Thinkpad Ultrabase), I don't think a new bug is needed.

> [10131.377840] [drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid,
> remainder is 67

For the EDID checksum error I already filed a bug at b.k.o:

https://bugzilla.kernel.org/show_bug.cgi?id=57461
Comment 11 Krzysiek Bielicki 2014-03-17 08:35:00 UTC 
DP works on 3.14.0-rc6.
Comment 12 Jani Nikula 2014-04-10 12:42:39 UTC 
(In reply to comment #11)
> DP works on 3.14.0-rc6.

Does the original problem persist with 3.14? Please try i915.i915_enable_fbc=0 module parameter and report back.
Comment 13 Jani Nikula 2014-05-07 12:41:57 UTC 
Does the problem persist? Please report back.
Comment 14 Krzysiek Bielicki 2014-05-07 12:43:02 UTC 
It works now.
Comment 15 Jani Nikula 2014-05-07 12:49:41 UTC 
(In reply to comment #14)
> It works now.

Thanks for the report and testing; I wish we knew what fixed it.
Comment 16 Jari Tahvanainen 2016-09-28 13:22:52 UTC 
It works, one does not exactly know what fixed the bug. Closing.

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