Bug 88590 - [hsw ult dp-to-vga] embedded DP-to-VGA output only works once
Summary: [hsw ult dp-to-vga] embedded DP-to-VGA output only works once
Status: CLOSED FIXED
Alias: None
Product: DRI
Classification: Unclassified
Component: DRM/Intel (show other bugs)
Version: XOrg git
Hardware: Other All
: medium normal
Assignee: Intel GFX Bugs mailing list
QA Contact: Intel GFX Bugs mailing list
URL:
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2015-01-19 16:12 UTC by Lucas Nussbaum
Modified: 2016-11-03 10:56 UTC (History)
1 user (show)

See Also:
i915 platform: HSW
i915 features: display/DP


Attachments
full dmesg during boot (100.55 KB, text/plain)
2015-01-19 16:12 UTC, Lucas Nussbaum
no flags Details
dmesg output when connecting projector to the VGA output (59.33 KB, text/plain)
2015-01-19 16:13 UTC, Lucas Nussbaum
no flags Details
xrandr output with the VGA (DP2) connected (5.35 KB, text/plain)
2015-01-19 16:13 UTC, Lucas Nussbaum
no flags Details
dmesg when disconnecting the VGA output (10.97 KB, text/plain)
2015-01-19 16:13 UTC, Lucas Nussbaum
no flags Details
dmesg when reconnecting VGA. DP2 stays "disconnected" in xrandr. (1.43 KB, text/plain)
2015-01-19 16:14 UTC, Lucas Nussbaum
no flags Details
dmesg with 3.19.0-rc5 (124.30 KB, text/plain)
2015-01-22 13:36 UTC, Lucas Nussbaum
no flags Details

Description Lucas Nussbaum 2015-01-19 16:12:15 UTC
Created attachment 112481 [details]
full dmesg during boot

Hi,

On a HP EliteBook 840 with a Intel HD 4400, the VGA output only works once.

Steps to reproduce:
1. boot
2. plug a project to the VGA output => works fine
3. unplug it
4. plug it again => doesn't work (shown as disconnected in xrandr)

Software versions & hardware:
Linux grr 3.18.0-trunk-amd64 #1 SMP Debian 3.18-1~exp1 (2014-12-11) x86_64 GNU/Linux

$ pkg-config --modversion libdrm ==> 2.4.58

(II) Module intel: vendor="X.Org Foundation"
     compiled for 1.16.2.901, module version = 2.99.917
(--) intel(0): Integrated Graphics Chipset: Intel(R) HD Graphics 4400

All attachments with drm.debug=0x06

Thanks!
Comment 1 Lucas Nussbaum 2015-01-19 16:13:04 UTC
Created attachment 112482 [details]
dmesg output when connecting projector to the VGA output
Comment 2 Lucas Nussbaum 2015-01-19 16:13:28 UTC
Created attachment 112483 [details]
xrandr output with the VGA (DP2) connected
Comment 3 Lucas Nussbaum 2015-01-19 16:13:46 UTC
Created attachment 112484 [details]
dmesg when disconnecting the VGA output
Comment 4 Lucas Nussbaum 2015-01-19 16:14:10 UTC
Created attachment 112485 [details]
dmesg when reconnecting VGA. DP2 stays "disconnected" in xrandr.
Comment 5 Lucas Nussbaum 2015-01-19 16:16:01 UTC
Note that it could be the same as bug 87736, but there wasn't enough information in that bug to ensure that it's really the same one.
Comment 6 Rodrigo Vivi 2015-01-22 00:16:04 UTC
Yes, it is the same. It is a issue with this dock firmware.

*** This bug has been marked as a duplicate of bug 87736 ***
Comment 7 Lucas Nussbaum 2015-01-22 06:42:54 UTC
oh, sorry, I misread bug 87736. In my case, the problem doesn't involve docking at all. (I'm booting out of the docking station, and using the laptop's VGA port)
Comment 8 Jani Nikula 2015-01-22 07:58:39 UTC
This is interesting, and the first I've seen. HP has picked up HSW ULT which does *not* have VGA, and has (apparently, per reference to "laptop's VGA port" in comment #7) embedded a DP-to-VGA converter in the box. Unfortunately, the converters, or dongles, are still quite unreliable and frankly I'm not quite sure why.

Please try v3.19-rc1 or later, or try cherry-picking

commit 19a93f042fc241ecdf98543cedfe7c171f8cdf53
Author: Dave Airlie <airlied@redhat.com>
Date:   Wed Nov 26 13:13:09 2014 +1000

    drm/dp: retry AUX transactions 32 times (v1.1)

to v3.18. The above commit is marked cc: stable, so it should eventually get backported to stable kernels. It should give the DP downstream a little more slack in responding; the legacy analog things may need that.
Comment 9 Lucas Nussbaum 2015-01-22 13:35:31 UTC
(In reply to Jani Nikula from comment #8)
> Please try v3.19-rc1 or later, or try cherry-picking
> 
> commit 19a93f042fc241ecdf98543cedfe7c171f8cdf53
> Author: Dave Airlie <airlied@redhat.com>
> Date:   Wed Nov 26 13:13:09 2014 +1000
> 
>     drm/dp: retry AUX transactions 32 times (v1.1)
> 
> to v3.18. The above commit is marked cc: stable, so it should eventually get
> backported to stable kernels. It should give the DP downstream a little more
> slack in responding; the legacy analog things may need that.

Hi,

I tried with 3.19.0-rc5, and the problem still occurs. I'm adding the dmesg output with drm.debug=0x06

Some more information:
There are two Ubuntu bug reports where users complain about the same problem (or at least some of the
posters do -- others are commenting about seemingly unrelated issues)
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1300914
https://bugs.launchpad.net/ubuntu/+source/libdrm/+bug/1411552

Comment 13 describes exactly the behaviour I'm seeing:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1300914/comments/13

Changing window manager (from GNOME to OpenBox) changes the behaviour:
- with OpenBox, switching to a TTY and then switching back to X "fixes"
  the problem.
- with GNOME, it does not.

However, I confirm that suspending/resuming "fixes" the problem (even with 
GNOME).
Comment 10 Lucas Nussbaum 2015-01-22 13:36:29 UTC
Created attachment 112663 [details]
dmesg with 3.19.0-rc5
Comment 11 Jani Nikula 2015-01-28 13:52:14 UTC
Please give this patch a try

http://mid.gmane.org/1422373429-10137-1-git-send-email-simon.farnsworth@onelan.co.uk
Comment 12 Lucas Nussbaum 2015-01-28 14:44:29 UTC
(In reply to Jani Nikula from comment #11)
> Please give this patch a try
> 
> http://mid.gmane.org/1422373429-10137-1-git-send-email-simon.
> farnsworth@onelan.co.uk

It does not change anything for me.
Comment 13 Lucas Nussbaum 2015-05-21 16:01:36 UTC
Note that if you are running into this, an easy way out is to just buy an external DisplayPort to VGA adapter for 10-15 EUR.
Comment 14 Jani Nikula 2015-10-23 10:38:51 UTC
We've since fixed plenty of DP aux/i2c-over-aux issues, so presumed fixed upstream. Please reopen if the problem persists with latest kernels.
Comment 15 Lucas Nussbaum 2015-10-28 11:55:51 UTC
> On a HP EliteBook 840 with a Intel HD 4400, the VGA output only works once.
> 
> Steps to reproduce:
> 1. boot
> 2. plug a project to the VGA output => works fine
> 3. unplug it
> 4. plug it again => doesn't work (shown as disconnected in xrandr)
> 
> Software versions & hardware:
> Linux grr 3.18.0-trunk-amd64 #1 SMP Debian 3.18-1~exp1 (2014-12-11) x86_64
> GNU/Linux
> 
> $ pkg-config --modversion libdrm ==> 2.4.58
> 
> (II) Module intel: vendor="X.Org Foundation"
>      compiled for 1.16.2.901, module version = 2.99.917
> (--) intel(0): Integrated Graphics Chipset: Intel(R) HD Graphics 4400

Hi,

I confirm that the above still happens with:
Linux grr 4.2.0-1-amd64 #1 SMP Debian 4.2.3-2 (2015-10-14) x86_64 GNU/Linux

$ pkg-config --modversion libdrm
2.4.64

[    12.284] (II) Module intel: vendor="X.Org Foundation"
[    12.284]    compiled for 1.17.2, module version = 2.99.917
[    12.284]    Module class: X.Org Video Driver
[    12.284]    ABI class: X.Org Video Driver, version 19.0

So, reopening as requested
Comment 16 Jani Nikula 2015-10-28 12:36:39 UTC
Please try v4.3-rc7.
Comment 17 Lucas Nussbaum 2015-11-03 09:12:45 UTC
(In reply to Jani Nikula from comment #16)
> Please try v4.3-rc7.

same with 4.3-rc7
Comment 18 Jani Nikula 2016-10-31 15:02:34 UTC
Seems we have neglected updating this bug more than a little; apologies. We have fixed a number of related issues, however. Is this still a problem with current kernels?
Comment 19 Lucas Nussbaum 2016-11-01 15:23:39 UTC
(In reply to Jani Nikula from comment #18)
> Seems we have neglected updating this bug more than a little; apologies. We
> have fixed a number of related issues, however. Is this still a problem with
> current kernels?

Yes (with 4.7 at least)
Comment 20 Jani Nikula 2016-11-01 15:35:40 UTC
How about current as in v4.9-rc3 or so? ;)
Comment 21 Lucas Nussbaum 2016-11-02 17:47:42 UTC
actually, it seems that this was fixed in 4.7.0. I did not notice because I'm so used to working-around this bug ;) Closing.
Comment 22 yann 2016-11-03 07:51:42 UTC
(In reply to Lucas Nussbaum from comment #21)
> actually, it seems that this was fixed in 4.7.0. I did not notice because
> I'm so used to working-around this bug ;) Closing.

Closing as fixed then
Comment 23 Jani Nikula 2016-11-03 10:56:38 UTC
(In reply to Lucas Nussbaum from comment #21)
> actually, it seems that this was fixed in 4.7.0. I did not notice because
> I'm so used to working-around this bug ;) Closing.

Awesome, thanks for the follow-up! \o/


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