3.5.7.11 -stable review patch. If anyone has any objections, please let me know.
------------------
From: Huacai Chen <chenhc@xxxxxxxxxx>
commit 6f389a8f1dd22a24f3d9afc2812b30d639e94625 upstream.
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@xxxxxxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
---
kernel/sys.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/kernel/sys.c b/kernel/sys.c
index b6fe559..0836a7f 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);
--
1.8.1.2
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