HDAPS

[Kay Sievers]

On Sun, 2006-10-01 at 23:06 +0100, Richard Hughes wrote:
> Guys,
> 
> HDAPS[1] (hard disk "drop" protection) is available in lots of new
> kernels for lots of new laptops.
> 
> To activate this, there is currently hdapsd[2] (a very small,
> unmaintained IMO hacky program) to monitor a
> hardcoded /sys/block/xxxx/queue/protect file, and if the acceleration is
> above a certain level, it parks the heads.
> 
> Now, I can see this implemented properly as an addon, only being
> launched when we have a new harddisk with HDAPS support, one addon per
> disk (tiny). Disks would also have the capability "hdaps_sensor".
> 
> Addon would have one method SetSensitivity() and two signals
> HDAPS-activated (bool) and HDAPS-motion (int) (or something).
> 
> This lets us park the heads to save the disk, and we can also use the
> motion signal to act as some sort of motion alarm / desktop lock in the
> desktop context.
> 
> Sound sane / insane? Comments?

How do you solve the problem with such a solution, that your
"emergency" code hasn't been swapped out when you detect that your laptop
is falling right now? I'm not sure, that you can solve such timing critical
problem in userspace.

Kay