Date: Mon, 5 Mar 2007 09:10:17 +0000 (UTC) From: Bruce Evans <bde@FreeBSD.org> To: src-committers@FreeBSD.org, cvs-src@FreeBSD.org, cvs-all@FreeBSD.org Subject: cvs commit: src/sys/i386/isa clock.c Message-ID: <200703050910.l259AHY8081078@repoman.freebsd.org>
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bde 2007-03-05 09:10:17 UTC
FreeBSD src repository
Modified files:
sys/i386/isa clock.c
Log:
Partial fix for a bug in rev.1.231. If suspend/resume clobbers the
RTC state, then it may clobber the RTC index register, so the index
register must be restored before using it to restore control registers
in rtc_restore().
The following problems remain:
- rtc_restore() is only called if pmtimer is configured. Buggy
suspend/resumes are more likely to clobber the index register than
a control register, so pmtimer is more needed than it used to be.
- pmtimer doesn't exist for amd64.
- Restoring of the RTC state may race with rtcintr(). If an RTC
interrupt is handled before the state is restored, then rtcin(RTC_INTR)
in rtcintr() may read from the wrong register, so rtcintr() may spin
forever. This may be mitigated by the most common state clobbering
being to turn off RTC interrupts.
Revision Changes Path
1.235 +1 -0 src/sys/i386/isa/clock.c
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