[ltp] radeonfb sleep patch for kernel 2.6.15

JP Renaud linux-thinkpad@linux-thinkpad.org
Tue, 20 Jun 2006 09:04:21 +0100


> Date: Tuesday 20 June 2006 07:34=20
> From: "Guarded Identity" <q507ddf02@sneakemail.com>
> 1) I've read that APM might offer significant savings in power lost during
> than ACPI S3. =A0Is this something that might have been true in the past,=
 but
> not so much these days? =A0Can APM do better than the 0.50 Watts I burn w=
ith
> S3? =A0I realize that a physical trial on my part is the best answer to t=
his.
> =A0 I'll try to get around to tinkering with the kernel sometime. =A0In t=
he
> meantime, maybe someone has an opinion.

apparently, you can tell suspend2 to suspend/resume via S3 after it wrote t=
he=20
image. so you can resume very quickly but if you run out of battery, a norm=
al=20
suspend2 resume can be used. then it takes a bit longer to suspend i suppos=
e=20
as the image still needs to be written.

here is the relevant extract from "man hibernate.conf":

=2D--
PowerdownMethod <3|4|5> (requires UseSuspend2 on)
                 Allows  you  to choose what Software Suspend 2 should do=20
after writing its image to disk. This only works if you have ACPI enabled i=
n=20
your kernel. 3/4/5 correspond to the  ACPI  states  S3  (suspend-to-RAM),  =
S4               =20
(suspend-to-disk),  and  S5 (power off). Choosing 3 will request your machi=
ne=20
to enter the S3 Suspend-to-RAM state if it is supported - this allows you=20
drastically cut the resume time waiting for your BIOS  but still  consumes =
=20
power  whilst hibernated (though the image is not lost should power run out=
).=20
Choosing 4 will cause your machine to enter an S4 sleep state which may als=
o=20
reduce the resume  time  without  using any  power  whilst  hibernated.=20
Choosing 5 will cause your machine to switch off after suspending (tradi =20
tional method).
=2D--

note that i've never actually used it...

=2D-=20
JP Renaud
Bristol, UK

http://www.jenny-and-jp.org (in English)
http://www.jenny-et-jp.org (en Fran=E7ais)