Re: notebook freezes

On Sunday 04 March 2007 13:27, Bruce Evans wrote:
> On Fri, 2 Mar 2007, Stefan Ehmann wrote:
> > On Thursday 01 March 2007 16:12, Stefan Ehmann wrote:
> >> My few days old -current freezes if I press Fn-F6 (this is the
> >> combination to adjust display brightness) if I've done a suspend/resume
> >> before. Directly after boot it works fine.
> >
> > ...
> > So I did a binary search.
> >
> > src/sys/i386/isa/clock.c r1.231 causes my notebook to freeze.
> >
> > Reverting this change in a CURRENT from today fixes the problem.
> >
> > The notebook is still pingable in this state. I experienced some other
> > random hangs recently but don't know yet if those are related.
>
> Oops.  If suspend/resume clobbers the RTC state (which we already have code
> to restore), then it can clobber the RTC index (which even the restoral
> code assumes is unclobbered).  Try this fix.
>
> %%%
> Index: clock.c
> ===================================================================
> RCS file: /home/ncvs/src/sys/i386/isa/clock.c,v
> retrieving revision 1.234
> diff -u -2 -r1.234 clock.c
> --- clock.c	4 Mar 2007 04:55:19 -0000	1.234
> +++ clock.c	4 Mar 2007 11:58:00 -0000
> _at__at_ -580,4 +582,5 _at__at_
>   	/* Restore all of the RTC's "status" (actually, control) registers. */
>   	/* XXX locking is needed for RTC access. */
> +	rtc_reg = -1;
>   	writertc(RTC_STATUSB, RTCSB_24HR);
>   	writertc(RTC_STATUSA, rtc_statusa);
> %%%
>
> A similar fix might be needed for amd64, but amd64 doesn't have a resume
> hook for putting it in.  The RTC index might get clobbered even if the
> data registers aren't.
>
> I don't know how any of this works with ACPI.  AFAIK (not far), the resume
> hook is only called for APM.

Yes, rtc_restore() doesn't get called. So the patch changes nothing for me.

Stefan