[ 009/171] MIPS: Fix poweroff failure when HOTPLUG_CPU configured.

From: Greg Kroah-Hartman
Date: Tue Jan 15 2013 - 17:45:04 EST


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

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

From: Huacai Chen <chenhc@xxxxxxxxxx>

commit 8add1ecb81f541ef2fcb0b85a5470ad9ecfb4a84 upstream.

When poweroff machine, kernel_power_off() call disable_nonboot_cpus().
And if we have HOTPLUG_CPU configured, disable_nonboot_cpus() is not an
empty function but attempt to actually disable the nonboot cpus. Since
system state is SYSTEM_POWER_OFF, play_dead() won't be called and thus
disable_nonboot_cpus() hangs. Therefore, we make this patch to avoid
poweroff failure.

Signed-off-by: Huacai Chen <chenhc@xxxxxxxxxx>
Signed-off-by: Hongliang Tao <taohl@xxxxxxxxxx>
Signed-off-by: Hua Yan <yanh@xxxxxxxxxx>
Cc: Yong Zhang <yong.zhang@xxxxxxxxxxxxx>
Cc: Fuxin Zhang <zhangfx@xxxxxxxxxx>
Cc: Zhangjin Wu <wuzhangjin@xxxxxxxxx>
Patchwork: https://patchwork.linux-mips.org/patch/4211/
Signed-off-by: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/mips/kernel/process.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

--- a/arch/mips/kernel/process.c
+++ b/arch/mips/kernel/process.c
@@ -72,9 +72,7 @@ void __noreturn cpu_idle(void)
}
}
#ifdef CONFIG_HOTPLUG_CPU
- if (!cpu_online(cpu) && !cpu_isset(cpu, cpu_callin_map) &&
- (system_state == SYSTEM_RUNNING ||
- system_state == SYSTEM_BOOTING))
+ if (!cpu_online(cpu) && !cpu_isset(cpu, cpu_callin_map))
play_dead();
#endif
rcu_idle_exit();


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