[ltp] Aggressive Powersaving

[Pedro Ribeiro]

2010/2/9 Henrique de Moraes Holschuh <hmh@hmh.eng.br>:
> On Tue, 09 Feb 2010, Karsten K=F6nig wrote:
>> the new kernels really brought down the power consumption and I am inter=
ested
>> in getting it a little bit further, on the road I don't use my DVD drive=
 nor
>> ExpressCard nor USB nor Firewire nor Touchpad, is there a way to cleany =
cut
>> the power to these devices/buses?
>
> Yes. =A0Disable them on the BIOS where possible, Linux doesn't put PCI de=
vices
> in D3 state yet as a rule, so once a driver loads and brings that device =
to
> D0 state, the device will stay powered up. =A0There might be exceptions.
>
> As for the DVD, eject the bay through sysfs (which will power it down wit=
h
> the device still inside), and tell the kernel to put the SATA link in the
> highest power saving mode (sysfs again).
>
>> I don't know about VGA and modem, but I think they aren't that easy acce=
ssible
>> because they are part of the graphics driver and alsa (it does drive the
>> winmodem right?)
>
> Disable the modem in the BIOS when not in use. =A0Same for serial ports, =
IR
> ports, the floppy controller, parallel ports...
>
> --
> =A0"One disk to rule them all, One disk to find them. One disk to bring
> =A0them all and in the darkness grind them. In the Land of Redmond
> =A0where the shadows lie." -- The Silicon Valley Tarot
> =A0Henrique Holschuh
> --
> The linux-thinkpad mailing list home page is at:
> http://mailman.linux-thinkpad.org/mailman/listinfo/linux-thinkpad
>

Hi Henrique,

I read somewhere (forgot where) that sata power management shouldn't
be messed with in hot swappable devices. But maybe that is not true on
later kernels?

Actually now that I think about it, since I use the DVD drive quite
sparingly, do you think it is a bad idea to have it on min_power all
the time? Will it affect my ability to watch DVD's etc?

Many thanks,
Pedro