Date: Wed, 27 Feb 2013 16:54:53 +0200 From: Andriy Gapon <avg@FreeBSD.org> To: Hans Petter Selasky <hps@bitfrost.no> Cc: freebsd-acpi@FreeBSD.org Subject: Re: ACPI locking bugs? Message-ID: <512E1E3D.7090501@FreeBSD.org> In-Reply-To: <201302271453.43985.hps@bitfrost.no> References: <201302271453.43985.hps@bitfrost.no>
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on 27/02/2013 15:53 Hans Petter Selasky said the following:
> Hi,
>
> What is the reason for using cv_wait_sig() and cv_timedwait_sig() instead of
> cv_wait() and cv_timedwait() inside of AcpiOsWaitSemaphore(). What signals are
> supposed to be catched here?
>
> switch (Timeout) {
> case ACPI_DO_NOT_WAIT:
> if (!ACPISEM_AVAIL(as, Units))
> status = AE_TIME;
> break;
> case ACPI_WAIT_FOREVER:
> while (!ACPISEM_AVAIL(as, Units)) {
> as->as_waiters++;
> error = cv_wait_sig(&as->as_cv, &as->as_lock);
> as->as_waiters--;
> if (error == EINTR || as->as_reset) {
> status = AE_ERROR;
> break;
> }
> }
> break;
> default:
> tmo = timeout2hz(Timeout);
> while (!ACPISEM_AVAIL(as, Units)) {
> prevtick = ticks;
> as->as_waiters++;
> error = cv_timedwait_sig(&as->as_cv, &as->as_lock,
> tmo);
> as->as_waiters--;
> if (error == EINTR || as->as_reset) {
> status = AE_ERROR;
> break;
> }
> if (ACPISEM_AVAIL(as, Units))
> break;
> slptick = ticks - prevtick;
> if (slptick >= tmo || slptick < 0) {
> status = AE_TIME;
> break;
> }
> tmo -= slptick;
> }
> }
>
> I've observed an issue twice on my MacBookPro that some ACPI locking fails
> during shutdown on 9-stable and then the power-off won't complete. I've been
> unable to capture the full dmesg, because syslogd is killed at the moment this
> happens. There are two ACPI error printouts about failed locking.
>
> I see that in the case of ACPI_WAIT_FOREVER, it appears to be incorrect to
> catch signals, because sometimes the return argument is not checked for lock
> operations:
>
> ./components/utilities/utosi.c: (void) AcpiOsAcquireMutex
> (AcpiGbl_OsiMutex, ACPI_WAIT_FOREVER);
> ./components/utilities/utosi.c: (void) AcpiOsAcquireMutex
> (AcpiGbl_OsiMutex, ACPI_WAIT_FOREVER);
> ./components/utilities/utosi.c: (void) AcpiOsAcquireMutex
> (AcpiGbl_OsiMutex, ACPI_WAIT_FOREVER);
>
> Any comments?
kib drew my attention to this issue some time ago and I also pinged jkim about it.
I completely agree with you that the signal handling should be removed.
Are you willing to make the change or would you prefer me doing it?
Thank you.
--
Andriy Gapon
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