[PATCH] MIPS: No need to check CPU 0 in cps_cpu_disable()

[PATCH] MIPS: No need to check CPU 0 in cps_cpu_disable()

[Tiezhu Yang]

After commit 9cce844abf07 ("MIPS: CPU#0 is not hotpluggable"),
c->hotpluggable is 0 for CPU 0 and it will not generate a control
file in sysfs for this CPU:

[root@linux loongson]# cat /sys/devices/system/cpu/cpu0/online
cat: /sys/devices/system/cpu/cpu0/online: No such file or directory
[root@linux loongson]# echo 0 > /sys/devices/system/cpu/cpu0/online
bash: /sys/devices/system/cpu/cpu0/online: Permission denied

So no need to check CPU 0 in cps_cpu_disable(), just remove it.

Reported-by: liwei (GF) <liwei391@huawei.com>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
---

cps_cpu_disable() is not done in the early similar patch,
sorry for that.

 arch/mips/kernel/smp-cps.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/arch/mips/kernel/smp-cps.c b/arch/mips/kernel/smp-cps.c
index 8b027c7..bcd6a94 100644
--- a/arch/mips/kernel/smp-cps.c
+++ b/arch/mips/kernel/smp-cps.c
@@ -451,9 +451,6 @@ static int cps_cpu_disable(void)
 	unsigned cpu = smp_processor_id();
 	struct core_boot_config *core_cfg;
 
-	if (!cpu)
-		return -EBUSY;
-
 	if (!cps_pm_support_state(CPS_PM_POWER_GATED))
 		return -EINVAL;
 
-- 
2.1.0

Re: [PATCH] MIPS: No need to check CPU 0 in cps_cpu_disable()

[Thomas Bogendoerfer]

On Tue, Dec 15, 2020 at 01:07:26PM +0800, Tiezhu Yang wrote:
> After commit 9cce844abf07 ("MIPS: CPU#0 is not hotpluggable"),
> c->hotpluggable is 0 for CPU 0 and it will not generate a control
> file in sysfs for this CPU:
> 
> [root@linux loongson]# cat /sys/devices/system/cpu/cpu0/online
> cat: /sys/devices/system/cpu/cpu0/online: No such file or directory
> [root@linux loongson]# echo 0 > /sys/devices/system/cpu/cpu0/online
> bash: /sys/devices/system/cpu/cpu0/online: Permission denied
> 
> So no need to check CPU 0 in cps_cpu_disable(), just remove it.
> 
> Reported-by: liwei (GF) <liwei391@huawei.com>
> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
> ---
> 
> cps_cpu_disable() is not done in the early similar patch,
> sorry for that.
> 
>  arch/mips/kernel/smp-cps.c | 3 ---
>  1 file changed, 3 deletions(-)

applied to mips-next.

Thomas.

-- 
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