Re: [linux-pm] [patch update 2 fix] PM: Introduce core framework for run-time PM of I/O devices

Oliver Neukum
2009-06-22T08:15:49Z

Am Montag, 22. Juni 2009 08:20:43 schrieb Magnus Damm:
> I'd like to call pm_request_suspend() from interrupt context. I don't
> depend on it, but being able to perform runtime suspend directly from
> the ISR would be convenient from a device driver POV. I'm not sure if
> that should result in bus/device ->runtime_suspend() calls from
> interrupt context though.
>
> In my case the bus specific code for ->runtime_suspend() may just
> decrease the usage count of the powerdomain but refrain from calling
> the device ->runtime_suspend() callbacks until all devices in the
> powerdomain have been suspended. The bus/device runtime suspend
> callbacks do not need to be executed from interrupt context. Just
> noting that the device is idle is enough at interrupt time. This could
> be handled by generic code IMO.

>From practical experience doing USB power management I can tell
you that requesting suspension from interrupt makes things a lot
easier for driver writers.

Regards
Oliver