Bug 2439

Summary:	S3 suspend: LCD backlight is white - Sharp PC-MM10
Product:	Drivers	Reporter:	Martin Lorenz (martin)
Component:	Video(Other)	Assignee:	Venkatesh Pallipadi (venki)
Status:	REJECTED UNREPRODUCIBLE
Severity:	high	CC:	acpi-bugzilla, richlv
Priority:	P2
Hardware:	i386
OS:	Linux
Kernel Version:	2.6.7 (but true for all earlyer 2.6.X too)	Subsystem:
Regression:	---	Bisected commit-id:

Description Martin Lorenz 2004-04-05 02:44:22 UTC

Full description of my system is available at BUG ID 1884 and 2438


When setting the system to S3 suspend mode it suspends nicely but the screen
gets bright white with backlight on instead of black and OFF

Comment 1 Martin Lorenz 2004-05-13 05:36:00 UTC

still true for 2.6.6-mm1

luming: could you give me a hint as to why you considered this important?
i'd like to contribute to a solution if it's that critical

Comment 2 Luming Yu 2004-05-17 23:09:38 UTC

  Recently, there are more and more S3 tickets  So S3 is becoming  critical. 
From this bug report, I doubt this box has ever been in S3 state successfully, 
because the blacklight should be shuted off.

  It's great , if you can find out a solution. May I assign this bug to you? :)

Thanks,
Luming

Comment 3 Martin Lorenz 2004-05-27 08:20:00 UTC

actually I am not quite sure if I know where to start from.
The possibility that my laptop is not propoerly going to S3 at all makes me
doubt I am able to find a solution.

I am still not sure it isen't caused by a buggy dsdt.

see http://bugzilla.kernel.org/show_bug.cgi?id=2438 for details on my attempts
to fix my dsdt...

greets
mlo

Comment 4 Len Brown 2004-11-15 21:08:36 UTC

please verify the problem still exists in 2.6.9 
 
Note that this may depend on the video controller: 
 
0000:00:09.0 VGA compatible controller: Silicon Motion, Inc. SM720 Lynx3DM (rev c1) (prog-if 
00 [VGA]) 
 
It also may depend on if you're running X, 
and the version of the X server.

Comment 5 Martin Lorenz 2004-11-16 00:33:36 UTC

it does

i made several attempts to solve the problem but finally decided to live
with it as the screen control keys now work properly and i can switch
off the screen before going to s3 - causing it to stay off in s3.

if you can give me instructions where to dig deeper i'll try my very
best.

I just tried with X11 shut off (stopped gdm and issued my sleep-scrit from the
commandline) and had the same effect...

Comment 6 Shaohua 2005-12-22 21:04:35 UTC

*** Bug 4390 has been marked as a duplicate of this bug. ***

Comment 7 Len Brown 2006-08-09 20:21:34 UTC

ACPI is not responsible for restoring video on S3 resume,
it is the job of the BIOS or video driver.  Moving this bug
to Drivers/Video.

Comment 8 Martin Lorenz 2006-08-28 12:07:52 UTC

IMHO this never was a resume issue...
the lcd backlight stayed ON on suspend and the screen went bright white.

it was still the same last time I used S3 on this machine with kernel 2.6.16.
in the meantime I retired this machine. so as far as I am concerned the bug
seems no longer relevant. but it obviously is still there.