Bug 87951 - [gen4] Hot plugged VGA output doesn't work
Summary: [gen4] Hot plugged VGA output doesn't work
Status: CLOSED FIXED
Alias: None
Product: DRI
Classification: Unclassified
Component: DRM/Intel (show other bugs)
Version: unspecified
Hardware: x86-64 (AMD64) Linux (All)
: medium normal
Assignee: Intel GFX Bugs mailing list
QA Contact: Intel GFX Bugs mailing list
URL:
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2015-01-01 20:21 UTC by o.j.woodford.98
Modified: 2017-05-31 13:02 UTC (History)
4 users (show)

See Also:
i915 platform: GM45
i915 features: display/Other


Attachments
Output of dmesg with drm.debug=6 (211.38 KB, text/plain)
2015-01-03 14:49 UTC, o.j.woodford.98
no flags Details
Output of dmesg with drm.debug=6 and VGA cable attached at boot up (164.60 KB, text/plain)
2015-01-04 10:21 UTC, o.j.woodford.98
no flags Details

Description o.j.woodford.98 2015-01-01 20:21:13 UTC
I have Toshiba Portege R600-10Q laptop (a model from 2009) which has an Intel GS45 graphics chipset. It ran Windows Vista when bought, and the VGA output worked as expected. 

I recently installed Ubuntu 14.04 64-bit on the laptop. When I have a VGA cable plugged in at boot up, the VGA output works fine. If instead I plug a VGA cable in after boot up, the external monitor is recognized, but receives no signal.This happens with several different monitors.

More details can be found here:
https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1364292
Comment 1 Chris Wilson 2015-01-01 20:49:00 UTC
Please retest with upstream components, see ppa:mainline for a drm-intel-nightly kernel.
Comment 2 o.j.woodford.98 2015-01-01 21:18:40 UTC
I have confirmed the bug exists with the following kernel:
3.19.0-031900rc2-generic #201412290135 SMP Mon Dec 29 01:36:54 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux
If you need more info you'll need to provide/link to more specific instructions, please.
Comment 3 Christopher M. Penalver 2015-01-01 22:33:06 UTC
o.j.woodford.98@cantab.net, what Chris Wilson is referring to is:
http://kernel.ubuntu.com/~kernel-ppa/mainline/drm-intel-nightly/

While testing 3.19-rc2 is good, drm-intel-nightly has newer commits specific to Intel (and not all found in 3.19-rc2) that may help further here.
Comment 4 Chris Wilson 2015-01-02 20:22:58 UTC
I think 3.19-rc2 should be recent enough (though if you can track -nightly that will help for future queries). Can you please now attach a dmesg from boot with drm.debug=6 on the kernel commandline?
Comment 5 o.j.woodford.98 2015-01-03 14:49:25 UTC
Created attachment 111687 [details]
Output of dmesg with drm.debug=6
Comment 6 o.j.woodford.98 2015-01-03 14:50:57 UTC
I've just tested with the current drm-intel-nightly kernel and the problem still exists. I've attached the output of dmesg.
Comment 7 Chris Wilson 2015-01-03 20:59:26 UTC
Ok. Does this happen for all the modes you try and set on the VGA monitor?

Could you also attach a drm.debug=6 for VGA attached from boot?
Comment 8 o.j.woodford.98 2015-01-04 10:21:21 UTC
Created attachment 111714 [details]
Output of dmesg with drm.debug=6 and VGA cable attached at boot up
Comment 9 o.j.woodford.98 2015-01-04 10:25:19 UTC
I've attached the dmesg output with VGA connected at input.

Some more comments on the behaviour:
 - The behaviour is the same whatever input the montior is set to, i.e. even if it is set to HDMI input, or even if it is on at all. (I assume this is what you mean by mode)
 - If the VGA cable was plugged in at boot then the hot swapping works as expected.
Comment 10 Chris Wilson 2015-01-04 20:52:24 UTC
Ah, I meant mode as in 1280x1024, 1024x768, 800x600 etc.

One difference between boot and hotplug is that at boot the bios brings it up at 1280x1024, but at hotplug it tries to use 1280x800. So I was just wondering if the lack of signal was just peculiar to one particular modeline.
Comment 11 o.j.woodford.98 2015-01-04 22:33:17 UTC
Changing the resolution output to the external monitor doesn't change the behaviour. It works fine when the cable was plugged in at boot. If it wasn't, nothing is displayed, regardless of the resolution.
Comment 12 Michael Hudson-Doyle 2015-03-17 21:11:17 UTC
Hi, just to say that I'm having the same problem on a similar sounding machine (a Portege A600) so if there is any more debugging or testing to be done I'm happy to have a go at it...
Comment 13 Jani Nikula 2016-01-18 13:06:00 UTC
Please try kernel v4.4.
Comment 14 Ricardo 2017-02-21 01:17:49 UTC
The request to test with a newer kernel was made months ago, if there is no response within a month the bug will be closed
Comment 15 Ricardo 2017-05-31 13:02:32 UTC
based on the lack of activity and response in the bug the bug will be closed, if the issue is detected in a newer configuration please open a new bug


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