notebook freezes

[John Baldwin]

On Thursday 08 March 2007 02:32, Bruce Evans wrote:
> On Wed, 7 Mar 2007, John Baldwin wrote:
> 
> > On Wednesday 07 March 2007 00:14, Bruce Evans wrote:
> >> I forgot to ask about the problem of interrupts racing with resume.
> >> What stops an interrupt occurring before the resume methods (the device
> >> method and all the ones above it) complete?  I don't know of any locking
> >> to prevent this or any way to detect this short of checking for magic
> >> garbage in device registers that have garbage in them because the
> >> registers are unmapped or just clobbered.  Can suspend happen
> >> asynchronously, so that it is possible for resume to deadlock on a
> >> resource locked by somthing which was interrupted for the suspend?
> >
> > I don't think there is stuff in there to protect against locks being held.
> > However, each device is supposed to turn its device off in it's
> > device_suspend() method and then turn it back on in device_resume() which
> > should resolve problems with garbage registers and spurious interrupts.
> 
> pmtimer doesn't do this of course.  Turning of RTC interrupts is easy,
> but turning off i8254 interrupts seems to require bus_teardown_intr().

Since the clocks aren't a new-bus device anyway, we can make them explicitly 
be suspended and resumed while interrupts are disabled for x86.

-- 
John Baldwin