[PATCH v5 2/3] ARM: rockchip: ensure CPU to enter WFI/WFE state

Caesar Wang wxt at rock-chips.com
Mon Jun 8 00:11:35 PDT 2015

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)
 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;

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