[PATCH] export-sysfs-of-debounce-time-of-ONKEY.patch

[Werner Almesberger]

matt_hsu wrote:
> This patch is a a band-aid solution to fix the following issue:
> 
> https://docs.openmoko.org/trac/ticket/1884

Hah, now I see what bug this one was about and that level-triggered
interrupts have been suggested before :-)

Holger and I discussed this one quite extensively on IRC earlier today.
The conclusion is that, indeed, switching to a level-triggered PMU
interrupt should solve this issue.

Reading back the GPIO in the last moment and aborting the suspend by
software would still leave a small race condition. We should consider
using that only in the unlikely case that the 2442 still goes to
suspend if a wakeup condition is already pending.

The other work-arounds are likely to introduce more issues, like
adding that parallel line to a CPU GPIO did in HXD8. (CPU could pull
nONKEY down during a shutdown, causing the PMU to power up. We solved
that somehow in hardware, but it wasn't nice.)

Holger is investigating trying the level-triggered interrupt now.

- Werner