The patch can ensure that v7_exit_coherency_flush() in rockchip_cpu_die()
executed in time.
The mdelay(1) has enough time to fix the problem of CPU offlining.
That's a workaround way in rockchip hotplug code,
At least, we haven't a better way to solve it. Who know,
that maybe fixed by chip (hardware) in the future.
Signed-off-by: Caesar Wang <wxt at rock-chips.com>
Changes in v5:
- Fix the patch decription.
- Add the changelog.
Changes in v4: None
Changes in v3: None
Changes in v2: None
Changes in v2:
- As Kever points out, Fix the subject typo WFI/WFE.
---
arch/arm/mach-rockchip/platsmp.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/arch/arm/mach-rockchip/platsmp.c b/arch/arm/mach-rockchip/platsmp.c
index bd40852..5bc2a89 100644
--- a/arch/arm/mach-rockchip/platsmp.c
+++ b/arch/arm/mach-rockchip/platsmp.c
@@ -321,6 +321,9 @@ static void __init rockchip_smp_prepare_cpus(unsigned int max_cpus)
#ifdef CONFIG_HOTPLUG_CPU
static int rockchip_cpu_kill(unsigned int cpu)
{
+ /* ensure CPU can enter the WFI/WFE state */
+ mdelay(1);
+
pmu_set_power_domain(0 + cpu, false);
return 1;
}
--
1.9.1
