cvs commit: src/sys/i386/bios apm.c
zec at icir.org
Wed Nov 14 07:28:25 PST 2007
On Wednesday 14 November 2007 10:01:32 Kris Kennaway wrote:
> Julian Elischer wrote:
> > julian 2007-11-14 05:43:55 UTC
> > FreeBSD src repository
> > Modified files:
> > sys/i386/bios apm.c
> > Log:
> > Apply the same sort of locking done in
> > sys/dev/acpica/acpi.c rev 1.196 a while ago:
> > Grab Giant around calls to DEVICE_SUSPEND/RESUME in
> > acpi_SetSleepState().
> > If we are resuming non-MPSAFE drivers, they need Giant held for
> > them. This may fix some obscure suspend/resume problems. It has
> > fixed keyrate setting problems that were triggered by cardbus
> > (MPSAFE) changing the ordering for syscons resume (non-MPSAFE).
> > Also, add some asserts that Giant is held in our suspend/resume and
> > shutdown methods.
> > Submitted by: Marko Zec
> > Revision Changes Path
> > 1.149 +10 -0 src/sys/i386/bios/apm.c
> Why are we adding new unconditional giant acquisitions to the tree?
> Devices indicate whether or not they are mpsafe, why can't this be
> made conditional?
In this case APM is the initiator, i.e. it is attempting to suspend /
resume all devices in the tree. If Giant is not held at that point,
suspend handlers for non-mpsafe won't get executed, and as a result
many such devices (USB in particular) won't work once the machine wakes
up. ACPI does exactly the same thing already.
Though I'm not sure if I've answered your question...
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