From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161597Ab3DGIiZ (ORCPT ); Sun, 7 Apr 2013 04:38:25 -0400 Received: from hydra.sisk.pl ([212.160.235.94]:53155 "EHLO hydra.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161511Ab3DGIiU (ORCPT ); Sun, 7 Apr 2013 04:38:20 -0400 From: "Rafael J. Wysocki" To: Huacai Chen , Andrew Morton Cc: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, Fuxin Zhang , stable@vger.kernel.org Subject: Re: [PATCH] PM/reboot: call syscore_shutdown() after disable_nonboot_cpus() Date: Sun, 07 Apr 2013 10:46 +0200 Message-ID: <3513307.9cks2gqsZt@vostro.rjw.lan> User-Agent: KMail/4.9.5 (Linux/3.9.0-rc4+; KDE/4.9.5; x86_64; ; ) In-Reply-To: <1365300854-3133-1-git-send-email-chenhc@lemote.com> References: <1365300854-3133-1-git-send-email-chenhc@lemote.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sunday, April 07, 2013 10:14:14 AM Huacai Chen wrote: > As commit 40dc166c (PM / Core: Introduce struct syscore_ops for core > subsystems PM) say, syscore_ops operations should be carried with one > CPU on-line and interrupts disabled. However, after commit f96972f2d > (kernel/sys.c: call disable_nonboot_cpus() in kernel_restart()), > syscore_shutdown() is called before disable_nonboot_cpus(), so break > the rules. We have a MIPS machine with a 8259A PIC, and there is an > external timer (HPET) linked at 8259A. Since 8259A has been shutdown > too early (by syscore_shutdown()), disable_nonboot_cpus() runs without > timer interrupt, so it hangs and reboot fails. This patch call > syscore_shutdown() a little later (after disable_nonboot_cpus()) to > avoid reboot failure, this is the same way as poweroff does. > > BTW, add disable_nonboot_cpus() in kernel_halt() for consistency. > > Signed-off-by: Huacai Chen > Cc: While I agree with the changes, I'm not sure if I'm the right maintainer, as this isn't really PM code. Andrew, should I take this? Rafael > --- > kernel/sys.c | 3 ++- > 1 files changed, 2 insertions(+), 1 deletions(-) > > diff --git a/kernel/sys.c b/kernel/sys.c > index 39c9c4a..0da73cf 100644 > --- a/kernel/sys.c > +++ b/kernel/sys.c > @@ -324,7 +324,6 @@ void kernel_restart_prepare(char *cmd) > system_state = SYSTEM_RESTART; > usermodehelper_disable(); > device_shutdown(); > - syscore_shutdown(); > } > > /** > @@ -370,6 +369,7 @@ void kernel_restart(char *cmd) > { > kernel_restart_prepare(cmd); > disable_nonboot_cpus(); > + syscore_shutdown(); > if (!cmd) > printk(KERN_EMERG "Restarting system.\n"); > else > @@ -395,6 +395,7 @@ static void kernel_shutdown_prepare(enum system_states state) > void kernel_halt(void) > { > kernel_shutdown_prepare(SYSTEM_HALT); > + disable_nonboot_cpus(); > syscore_shutdown(); > printk(KERN_EMERG "System halted.\n"); > kmsg_dump(KMSG_DUMP_HALT); > -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center.