Date: Sat, 31 Mar 2007 11:37:57 +0200 From: Stefan Ehmann <shoesoft@gmx.net> To: Bruce Evans <bde@zeta.org.au> Cc: freebsd-current@freebsd.org Subject: Re: notebook freezes Message-ID: <200703311137.59128.shoesoft@gmx.net> In-Reply-To: <20070304230346.O7298@besplex.bde.org> References: <200703011612.07110.shoesoft@gmx.net> <200703021619.33755.shoesoft@gmx.net> <20070304230346.O7298@besplex.bde.org>
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On Sunday 04 March 2007 13:27:48 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 > @@ -580,4 +582,5 @@ > /* 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); > %%% For some odd reason, the problem has returned. I'm pretty sure that I've built a kernel shortly after your commit and it just worked fine. Now the problem persists when I build a kernel with sources from that date. I'm not aware of any big changes I made to my configuration. I checked that rtc_restore() gets called. Either I screwed up something last time or some changes in the userland expose a race (I only rebuilt kernel from older sources, not world). Backing out the changes made in 1.231 still fixes the problem. Stefan
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