From: Thomas Gleinxer Date: Fri, 14 Oct 2011 11:44:41 +0000 (+0100) Subject: ARM: 7133/1: SMP: fix per cpu timer setup before the cpu is marked online X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=eb0474544bc16a9dab53b26abd846e86ba814eb1;p=GitHub%2FLineageOS%2Fandroid_kernel_samsung_universal7580.git ARM: 7133/1: SMP: fix per cpu timer setup before the cpu is marked online The problem is related to the early enabling of interrupts and the per cpu timer setup before the cpu is marked online. This doesn't need to be done in order to call calibrate_delay(). calibrate_delay() monitors jiffies, which are updated from the CPU which is waiting for the new CPU to set the online bit. So simply calibrate_delay() can be called on the new CPU just from the interrupt disabled region and move the local timer setup after stored the cpu data and before enabling interrupts. This solves both the cpu_online vs. cpu_active problem and the affinity setting of the per cpu timers. Signed-off-by: Thomas Gleinxer Signed-off-by: Kukjin Kim Signed-off-by: Russell King --- diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index d88ff0230e8..697e9a8cbdd 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -301,17 +301,7 @@ asmlinkage void __cpuinit secondary_start_kernel(void) */ platform_secondary_init(cpu); - /* - * Enable local interrupts. - */ notify_cpu_starting(cpu); - local_irq_enable(); - local_fiq_enable(); - - /* - * Setup the percpu timer for this CPU. - */ - percpu_timer_setup(); calibrate_delay(); @@ -323,9 +313,22 @@ asmlinkage void __cpuinit secondary_start_kernel(void) * before we continue. */ set_cpu_online(cpu, true); + + /* + * Setup the percpu timer for this CPU. + */ + percpu_timer_setup(); + while (!cpu_active(cpu)) cpu_relax(); + /* + * cpu_active bit is set, so it's safe to enalbe interrupts + * now. + */ + local_irq_enable(); + local_fiq_enable(); + /* * OK, it's off to the idle thread for us */