Bug 668297

Summary:	upower causing black flashing screen
Product:	[Fedora] Fedora	Reporter:	Tom <thomasbelvin>
Component:	upower	Assignee:	Richard Hughes <rhughes>
Status:	CLOSED CURRENTRELEASE	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	medium	Docs Contact:
Priority:	low
Version:	rawhide	CC:	airlied, ajax, awilliam, bruno, bskeggs, henriquecsj, rhughes, richard
Target Milestone:	---	Keywords:	Triaged
Target Release:	---
Hardware:	i686
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2011-03-24 11:04:09 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Tom 2011-01-09 21:27:17 UTC

Description of problem:
Latest upower causing black flashing screen. When screen flashes, I get:
"[drm] nouveau 0000:01:00.0: Load detected on output A"

Version-Release number of selected component (if applicable):
upower-0.9.8-1.fc15 causes problems, upower-0.9.7-2.fc15 works fine

How reproducible:
Everytime

Steps to Reproduce:
1.Update upower
2.Screen starts flashing black
3.Downgrade upower, screen works fine
  
Actual results:
Screen flashes black for a couple of seconds, then again less than a minute later.

Expected results:
Steady screen

Additional info:

Comment 1 Richard Hughes 2011-01-10 09:15:35 UTC

upower uses the drm state to detect if the laptop is docked or not. I'm guessing you also get the blanking when you do:

cat /sys/class/drm/*/status

as a normal user. If so, that's a nouveau bug, and a fairly serious DOS if that's the case.

Comment 2 Tom 2011-01-10 10:46:52 UTC

Yes, I get that blanking screen with cat /sys/class/drm/*/status and it says:
disconnected
disconnected
connected

I get this error on an old desktop.

Comment 3 Adam Williamson (Red Hat non-Fedora) 2011-01-11 17:28:32 UTC


-- 
Fedora Bugzappers volunteer triage team
https://fedoraproject.org/wiki/BugZappers

Comment 4 Bruno Wolff III 2011-01-17 03:43:05 UTC

I am seeing what seems to be the same thing on a desktop system with an nv28. The screen blanks briefly about every 30 seconds.

Comment 5 Bruno Wolff III 2011-01-17 16:13:22 UTC

This is also happening on my rv280 system. It's just that the blink is much shorter. It happens every 30 seconds.

Comment 6 Bruno Wolff III 2011-02-06 06:00:08 UTC

Related to this is that the nouveau driver (but not radeon) will write a console message for each of these checks. This makes using vts a pain.

Comment 7 Bruno Wolff III 2011-03-05 16:04:14 UTC

This is still happening with kernel-PAE-2.6.38-0.rc7.git2.3.fc15.i686 and xorg-x11-drv-nouveau-0.0.16-20.20110224gitbc5dec2.fc15.i686.

Comment 8 Richard Hughes 2011-03-07 09:33:34 UTC

FWIW, I applied this the other day:

commit 38199e44ff1e87b586d51d30b69d1f70e40d27f1
Author: Richard Hughes <richard>
Date:   Thu Mar 3 14:02:27 2011 +0000

    Add an option for polling dock devices in UPower.conf, defaulting to false

So now we're relying on the kernel to do the polling for us. If that doesn't work the user can re-enable the userspace poll in a config file.

Comment 9 Bruno Wolff III 2011-03-07 13:39:02 UTC

That may help, but it still seems like there is a bug in the drivers.

Comment 10 Bruno Wolff III 2011-03-20 16:54:42 UTC

The last upower build is from before that change. Is there going to be a new one soon?

Comment 11 Ben Skeggs 2011-03-20 23:08:15 UTC

It's not a bug in the drivers, such blinking is unavoidable with VGA load detection.  I don't know about radeon, but nouveau tries its very best to avoid causing the screen to flicker when doing load detection.  It does this by:

1. using an unused CRTC (if there's any available) while doing the probe, and
2. not polling for VGA disconnects when a mode is set on a VGA output

If upower is sitting there explicitly asking us to reprobe whether a connected VGA monitor has disappeared, there's *nothing* we can do.  So, reassigning to upower until the upstream fix has made it into the fedora package.

Comment 12 Ben Skeggs 2011-03-20 23:08:41 UTC

*** Bug 678381 has been marked as a duplicate of this bug. ***

Comment 13 Bruno Wolff III 2011-03-22 14:12:35 UTC

This no longer happens with upower-0.9.9-1.fc15.i686.
Thanks.