[PATCH] ARM: mvebu: Disable CPU Idle on Armada 38x

[Gregory CLEMENT]

On Armada 38x SoCs, under heavy I/O load, the system hangs when CPU
Idle is enabled. Waiting for a solution to this issue, this patch
disables the CPU Idle support for this SoC.

As CPU Hot plug support also uses some of the CPU Idle functions it is
also affected by the same issue. This patch disables it also for the
Armada 38x SoCs.

Signed-off-by: Gregory CLEMENT <gregory.clement at free-electrons.com>
Cc: <stable at vger.kernel.org> # v3.17 +
---
 arch/arm/mach-mvebu/pmsu.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/arch/arm/mach-mvebu/pmsu.c b/arch/arm/mach-mvebu/pmsu.c
index d8ab605a44fa..05c8625bbc40 100644
--- a/arch/arm/mach-mvebu/pmsu.c
+++ b/arch/arm/mach-mvebu/pmsu.c
@@ -476,12 +476,22 @@ static int __init mvebu_v7_cpu_pm_init(void)
 		return 0;
 	of_node_put(np);
 
+	/*
+	 * Currently the CPU Idle support for Armada 38x is broken, as
+	 * the CPU Hotplug uses some of the CPU Idle functions it is
+	 * broken too, so let's disable it
+	 */
+	if (of_machine_is_compatible("marvell,armada380")) {
+		cpu_hotplug_disable();
+		pr_warn("CPU Hotplug support is currently broken on Armada 38x: disabling");
+	}
+
 	if (of_machine_is_compatible("marvell,armadaxp"))
 		ret = armada_xp_cpuidle_init();
 	else if (of_machine_is_compatible("marvell,armada370"))
 		ret = armada_370_cpuidle_init();
-	else if (of_machine_is_compatible("marvell,armada380"))
-		ret = armada_38x_cpuidle_init();
+	else if (of_machine_is_compatible("marvell,armada380")
+		 pr_warn("CPU Idle is currently broken on Armada 38x: disabling");
 	else
 		return 0;
 
-- 
2.1.0