[laptop-mode] RFC: USB disk spindown script

[Bart Samwel]

Hi Johannes,

Johannes Niess wrote:
> as laptop-mode is mostly concerned with disk spindown, my post might be on 
> topic. I'd like to hear your comments about a possible solution to a common 
> problem.
> 
> Most USB disk vendors include a proprietary spindown application for Windows, 
> but nothing for Linux. With the current state of USB SCSI implementation in 
> Linux only a few commands get executed on the IDE or SATA disk. The 
> native "hdparm -S" or typical SCSI commands won't work to spin down USB 
> disks. I've no idea about firewire.
> 
> I found some forum posts on using 'sdparm -C stop', but no suggested mechanism 
> to track disk usage. I've written a poor mans implementation to spin down USB 
> disks after inactivity. It is quite similar to 'smart spindown'.

Now that's interesting. I've always wondered if there would be something
to do that, and apparently there is. In its current state I can't
include this in laptop-mode-tools, but would it be an idea to write a
laptop-mode-tools module that automatically starts off a process for
doing this, depending on the power state etc.? I could definitely
include something like that -- and it would be a very useful addition.

Cheers,
Bart