Bug 4205

Summary:	S3 suspend: Backlight stays on - IBM Thinkpad X31
Product:	ACPI	Reporter:	Josef Gasteiger (linux-versand)
Component:	Power-Sleep-Wake	Assignee:	Rafael J. Wysocki (rjwysocki)
Status:	CLOSED INSUFFICIENT_DATA
Severity:	normal	CC:	acpi-bugzilla, mjg59-kernel
Priority:	P2
Hardware:	i386
OS:	Linux
Kernel Version:	2.6.11r4	Subsystem:
Regression:	---	Bisected commit-id:

Description Josef Gasteiger 2005-02-13 03:25:26 UTC

Distribution: Debian Sarge
Hardware Environment: IBM Thinkpad X31 with radeon card
Software Environment: kernel 2.6.11r4
Problem Description: When going in S3 mode the display turns off for a second,
but then the backlight goes on again.
With kernel 2.6.10 the backlight stayed off.

Steps to reproduce: 
Here is the .config file: http://ro-wetter.dyndns.org/pics/.config2

Comment 1 Matthew Garrett 2005-02-13 16:04:24 UTC

Install vbetool (it's in Sarge now) and run vbetool dpms off at the end of your
suspend script.

Comment 2 Josef Gasteiger 2005-02-14 01:19:30 UTC

Thanks, but the backlight still goes on.

My script looks like this (hope that's what you meant):
...
vbetool dpms off
echo -n 3 > /proc/acpi/sleep
...

Comment 3 Rafael J. Wysocki 2006-09-28 16:25:45 UTC

Please reopen if the problem is still present in recent kernels (2.6.18 and later).

Comment 4 Pavel Machek 2006-09-29 03:59:48 UTC

Actually, the problem _is_ present with new kernels, but it is not kernel
problem. Either run radeontool to turn off backlight, or better install s2ram
from suspend.sf.net.