From owner-freebsd-acpi@FreeBSD.ORG  Wed Feb 27 13:52:35 2013
Return-Path: <owner-freebsd-acpi@FreeBSD.ORG>
Delivered-To: freebsd-acpi@freebsd.org
Received: from mx1.freebsd.org (mx1.FreeBSD.org [8.8.178.115])
 by hub.freebsd.org (Postfix) with ESMTP id 81350747
 for <freebsd-acpi@freebsd.org>; Wed, 27 Feb 2013 13:52:35 +0000 (UTC)
 (envelope-from hps@bitfrost.no)
Received: from mta.bitpro.no (mta.bitpro.no [92.42.64.202])
 by mx1.freebsd.org (Postfix) with ESMTP id 18A141CF
 for <freebsd-acpi@freebsd.org>; Wed, 27 Feb 2013 13:52:34 +0000 (UTC)
Received: from mail.bitfrost.no (mail.bitfrost.no [46.29.221.36])
 by mta.bitpro.no (Postfix) with ESMTP id 54FC47A123
 for <freebsd-acpi@freebsd.org>; Wed, 27 Feb 2013 14:52:34 +0100 (CET)
X-Virus-Scanned: Debian amavisd-new at bitfrost.no
Received: from smtp.bitfrost.no (cm-176.74.213.204.customer.telag.net
 [176.74.213.204])
 (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits))
 (No client certificate requested) (Authenticated sender: hanspetter)
 by mail.bitfrost.no (Postfix) with ESMTPSA id 7A77720D01
 for <freebsd-acpi@freebsd.org>; Wed, 27 Feb 2013 14:52:28 +0100 (CET)
From: Hans Petter Selasky <hps@bitfrost.no>
Organization: Bitfrost A/S
To: freebsd-acpi@freebsd.org
Subject: ACPI locking bugs?
Date: Wed, 27 Feb 2013 14:53:43 +0100
X-Face: ?p&W)c<w+fb'sd#*]i!s!UQ[!|W8%I(I+\}LQ-Z1nB*t(u_>(
 =?utf-8?q?+80hU=3B=27=7B=2E=245K+zq=7BoC6y=7C=0A=09/D=27an*6mw?=>j'f:eBsex\Gi,
 <a&s"J*gPjz0nO, Sucb&N84|zkA2YlM?`/Vp=@
 =?utf-8?q?Bh=7DpyW=3DTQ=0A=09WtqwY=27=5FSy0aa=7E?=(jJCeFpDW
MIME-Version: 1.0
Content-Type: text/plain;
  charset="us-ascii"
Content-Transfer-Encoding: 7bit
Message-Id: <201302271453.43985.hps@bitfrost.no>
X-BeenThere: freebsd-acpi@freebsd.org
X-Mailman-Version: 2.1.14
Precedence: list
List-Id: ACPI and power management development <freebsd-acpi.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/options/freebsd-acpi>,
 <mailto:freebsd-acpi-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-acpi>
List-Post: <mailto:freebsd-acpi@freebsd.org>
List-Help: <mailto:freebsd-acpi-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-acpi>,
 <mailto:freebsd-acpi-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Wed, 27 Feb 2013 13:52:35 -0000

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?

Reference: sys/dev/acpica/Osd/OsdSynch.c:AcpiOsWaitSemaphore

--HPS