[045/126] PM / reboot: call syscore_shutdown() after disable_nonboot_cpus()

Steven Rostedt
2013-05-07T04:01:32Z

[-- Attachment #1: 0045-PM-reboot-call-syscore_shutdown-after-disable_nonboo.patch --]
[-- Type: text/plain, Size: 2039 bytes --]

3.6.11.3 stable review patch.
If anyone has any objections, please let me know.

------------------

From: Huacai Chen <chenhc@lemote.com>

[ Upstream commit 6f389a8f1dd22a24f3d9afc2812b30d639e94625 ]

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.

For consistency, add disable_nonboot_cpus() to kernel_halt().

Signed-off-by: Huacai Chen <chenhc@lemote.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
kernel/sys.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/sys.c b/kernel/sys.c
index 909148a..61c086b7 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -323,7 +323,6 @@ void kernel_restart_prepare(char *cmd)
system_state = SYSTEM_RESTART;
usermodehelper_disable();
device_shutdown();
- syscore_shutdown();
}

/**
@@ -369,6 +368,7 @@ void kernel_restart(char *cmd)
{
kernel_restart_prepare(cmd);
disable_nonboot_cpus();
+ syscore_shutdown();
if (!cmd)
printk(KERN_EMERG "Restarting system.\n");
else
@@ -394,6 +394,7 @@ 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);
--
1.7.10.4