Bug 668297 - upower causing black flashing screen
Summary: upower causing black flashing screen
Keywords:
Status: CLOSED CURRENTRELEASE
Alias: None
Product: Fedora
Classification: Fedora
Component: upower
Version: rawhide
Hardware: i686
OS: Linux
low
medium
Target Milestone: ---
Assignee: Richard Hughes
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard:
: 678381 (view as bug list)
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2011-01-09 21:27 UTC by Tom
Modified: 2011-03-24 11:04 UTC (History)
8 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2011-03-24 11:04:09 UTC
Type: ---
Embargoed:


Attachments (Terms of Use)

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 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.


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