Re: APM & device_power_up/down

[Michael Schierl]

On Mon, 01 Mar 2004 09:20:07 +0100, in linux.kernel you wrote:

>Hi all!
>
>I've tried to contact Pavel Machek directly, but got no response from him, so I'm forwarding the letter to the list.
>
>The problem is: 
>the patch, that was provided here: 
>http://marc.theaimsgroup.com/?l=linux-kernel&m=107540713415651&w=2, 
>prevents my laptop from suspending.

Hmm. Can you try unapplying it and applying the one in 

http://marc.theaimsgroup.com/?l=linux-kernel&m=107506063605497&w=2

instead? Does it work for you as well as with no patch?

>This behaviuor was firstly noticed after upgrade from 2.6.1 to 2.6.2 (and 2.6.3 doesn't fix it).

>So I decided to do a small investigation and discovered that when I 
>remove calls to device_power_*() from apm.c, it works well.

My situation is the other way round. I was always unable to suspend my
laptop under Linux until I tried the 2.5.x series first. That one
worked; however, in 2.6.0-test4 someone did some major changes and
removed these two calls as well. So I could not suspend in 2.6.0-test4
till 2.6.1, now U can again :-)

>Of course, the problem can be in my laptop's BIOS or wherever, but, I 
>repeat, it works well with 2.4.x & 2.6.1 and it doesn't with 2.6.2 & 
>2.6.3.

Same for me. Dunno if my or your BIOS is borked, but one is surely
broken.

>At this moment I can hardly understand why there is need to power down 
>devices after suspend (shouldn't they be powered down in the suspend 
>process?), but I'm not a kernel hacker.

Where do you read something about powering down devices after suspend?

The process is:

1- suspend devices

2- (power down devices w/ my patch)

3- asm call to put cpu in suspend mode - it will not return 
   until you wake it up again

4- (power up devices w/ my patch)

5- resume devices

>So, any help is appreciated.

HTH,

Michael
-- 
My PGP Key: User ID: Michael Schierl <schierlm@xxxxxx>
Key ID: 0x58B48CDD    Size: 2048    Created: 26.03.2002
Fingerprint:  68CE B807 E315 D14B  7461 5539 C90F 7CC8
http://home.arcor.de/mschierlm/mschierlm.asc
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/