Re: Resume -> higher power drain?

[Nils Faerber <nils.faerber-t93Ne7XHvje5bSeCtf/tX7NAH6kLmebB@public.gmane.org>]

[-- Attachment #1: Type: text/plain, Size: 1354 bytes --]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Pavel Machek wrote:
> Hi!
Hi!

>>The problem seemed to be related to suspend/resume scripts, so to say. I
>>did enable vbetool to save/restore VESA state and doing vbetool post.
>>
>>Using s3_bios resume this is not necessary!
>>
>>And after disabling vbetool usage at all the bus master activity is back
>>to normal again after resume!
>>
>>So at least for my T42p I can recommend NOT to use vbetool at all for
>>suspend/resume but rather to use s3_bios!
> 
> Can you suggest a patch to Documentation/power/video.txt?

I changed the file a little accordingly, a diff is attached.
I think it would be a good idea to start some compatibitlity
documentation, i.e. which device is known to work with which
options/tricks. I appended a "compatibility matrix" to the end of the file.

Tel me if you find this documentation useful or what can/should be
added/changed.

> 								Pavel
CU
  nils faerber

- --
kernel concepts          Tel: +49-271-771091-12
Dreisbachstr. 24         Fax: +49-271-771091-19
D-57250 Netphen          Mob: +49-176-21024535
- --
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.0 (GNU/Linux)
Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org

iD8DBQFCfUbdJXeIURG1qHgRAvmuAJ4/Q1a7HCdeNmpC3MtsGzQ3Z1Xl0QCdGlmz
T5SUaUZCiGtraA/Zc4zIcFY=
=aKR1
-----END PGP SIGNATURE-----

[-- Attachment #2: video.txt.diff --]
[-- Type: text/x-patch, Size: 2736 bytes --]

*** linux-2.6.11.8/Documentation/power/video.txt-o	Sun May  8 00:48:38 2005
--- linux-2.6.11.8/Documentation/power/video.txt	Sun May  8 00:45:58 2005
***************
*** 36,43 ****
  Now, if you pass acpi_sleep=something, and it does not work with your
  bios, you'll get hard crash during resume. Be carefull.
  
! You may have system where none of above works. At that point you
  either invent another ugly hack that works, or write proper driver for
  your video card (good luck getting docs :-(). Maybe suspending from X
  (proper X, knowing your hardware, not XF68_FBcon) might have better
  chance of working.
--- 36,84 ----
  Now, if you pass acpi_sleep=something, and it does not work with your
  bios, you'll get hard crash during resume. Be carefull.
  
! You may have a system where none of above works. At that point you
  either invent another ugly hack that works, or write proper driver for
  your video card (good luck getting docs :-(). Maybe suspending from X
  (proper X, knowing your hardware, not XF68_FBcon) might have better
  chance of working.
+ 
+ 
+ Other well known solutions to get your video back on resume using vbetool.
+ Vbetool can execude the real-mode video BIOS extension and use standard
+ video BIOS calls to alter the hardware state of your video hardware. There
+ are two ways to get video to resume:
+ 
+ * save your current video setting before going to suspend and restore it on
+   resume, like
+ 	vbetool save > /tmp/.vbe-settings
+ 	[go to sleep]
+ 	vbetool restore < /tmp/.vbe-settings
+   On many systems this will bring back your complete video hardware,
+   including backlight on notebook TFTs. This is known to work with many ATI
+   radeon systems and Intel Centrino.
+ 
+ * manually execute the video post method if you BIOS does not do it for you,
+   again vbetool can do this
+ 	vbetool post
+   This can on some systems already be enough to get your video back.
+ 
+ Warning: The above should only be tested in a safe environment like a single
+ user shell since it may be necessary to cold-reset your machine, your
+ machine might not resume correctly or simply crash hard.
+ 
+ 
+ Compatibility matrix for S3 resume:
+ 
+ Machine		s3_bios s3_mode vbe-save vbe-post recommended
+ -------------------------------------------------------------
+ HP Omnibook xe3s
+   Athlon           -       -       -        -        no special action required
+ IBM T42p           X       ?       X        X        s3_bios, vbe methods result in CPU bus master activity madness
+ Toshiba 4030cdt            X                         s3_mode
+ Toshiba Satellite
+   P10-554          X       X                         s3_bios,s3_mode
+ 
+ 
+ X = working
+ ? = unknown
+ - = not action required