[Hdaps-devel] Re: [ltp] IBM HDAPS Someone interested? (Accelerometer)

Shawn Starr linux-thinkpad@linux-thinkpad.org
Sun, 26 Jun 2005 23:35:15 -0400


Perhaps a kernel space daemon but with some ioctls that userspace can 
manipulate?

Or can the whole daemon be offloaded to userspace? Having some driver ioctls 
and a sysfs interface would allow the KDE and GNOME people to read the sysfs 
info and parse accordingly for some nifty tools.

Sounds good?

Shawn.


On June 25, 2005 16:09, Vojtech Pavlik wrote:
> On Sat, Jun 25, 2005 at 01:13:17PM -0500, Alejandro Bonilla wrote:
> > I have a question here, how do you guys think that the head is parked,
> > is it done by the controller directly, which then sends the command to
> > the HD to park the head, or this is done by the operating system in some
> > kind of way?
> >
> > I think the OS or user space is too slow like to react to send a park
> > command to the hard drive, so this most be done directly by the embedded
> > controller, but still I think it needs some input from the OS, to
> > initialize it's settings.
>
> The only way to park a drive is to send a command to it through the IDE
> interface. This can't be done by the controller itself, since the
> controller in the ThinkPad is a classic Intel ICH chip which only passes
> commands around.
>
> The OS is definitely fast enough for this kind of task, it's doable even
> in userspace, although not easy.
>
> > i.e. after all, in windows you do have the settings in the software
> > for HDAPS, but it looks like it is _not_ managed by the operating
> > system at all if there is some type of action to  be taken. This is
> > also probably why HDAPS won't kick in until booted, and that is
> > because it needs to load its config setup by the software.
> >
> > This is what I think, please correct me if I'm saying something crazy.
>
> It is definitely all done by the windows kernel driver.