notebook freezes

[Bruce Evans]

[Trying to redirect this from current to acpi.]

On Sun, 4 Mar 2007, Stefan Ehmann wrote:

> 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
>> @@ -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);
>> %%%
>>
>> 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

Bruce