ARM: imx: disable cpu in .cpu_kill hook

It's buggy to disable the cpu that is being hot-unplugged in .cpu_die
hook which runs on the cpu itself.  Instead, it should be done in
.cpu_kill which runs on the thread (another cpu) that asks for shutting
down the cpu.  Move imx_enable_cpu(cpu, false) call into .cpu_kill
hook, and leave the cpu to be hot-unplugged in WFI within .cpu_die,
so that we can get a more stable cpu hot-plug operation.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>

1 files changed, 6 insertions, 4 deletions

diff --git a/arch/arm/mach-imx/hotplug.c b/arch/arm/mach-imx/hotplug.c
index 3dec962..7bc5fe1 100644
--- a/arch/arm/mach-imx/hotplug.c
+++ b/arch/arm/mach-imx/hotplug.c
@@ -46,9 +46,11 @@ static inline void cpu_enter_lowpower(void)
 void imx_cpu_die(unsigned int cpu)
 {
 	cpu_enter_lowpower();
-	imx_enable_cpu(cpu, false);
+	cpu_do_idle();
+}
 
-	/* spin here until hardware takes it down */
-	while (1)
-		;
+int imx_cpu_kill(unsigned int cpu)
+{
+	imx_enable_cpu(cpu, false);
+	return 1;
 }