mvebu: disable cpu idle on a38x

Signed-off-by: Imre Kaloz <kaloz@openwrt.org>

SVN-Revision: 45302

1 files changed, 62 insertions, 0 deletions

diff --git a/target/linux/mvebu/patches-4.0/031-disable_cpu_idle_on_armada_38x.patch b/target/linux/mvebu/patches-4.0/031-disable_cpu_idle_on_armada_38x.patch
new file mode 100644
index 0000000000..31a73a504c
--- /dev/null
+++ b/target/linux/mvebu/patches-4.0/031-disable_cpu_idle_on_armada_38x.patch
@@ -0,0 +1,62 @@
+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@free-electrons.com>
+Tested-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
+Cc: <stable@vger.kernel.org> # v3.17 +
+---
+Hi,
+
+In this version I removed the unneeded initialization of the ret
+variable, I also fixed the warning message, and finally I added the
+Tested-by from Thomas.
+
+Gregory
+
+ arch/arm/mach-mvebu/pmsu.c | 16 +++++++++++++++-
+ 1 file changed, 15 insertions(+), 1 deletion(-)
+
+--- a/arch/arm/mach-mvebu/pmsu.c
++++ b/arch/arm/mach-mvebu/pmsu.c
+@@ -415,6 +415,9 @@ static __init int armada_38x_cpuidle_ini
+ 	void __iomem *mpsoc_base;
+ 	u32 reg;
+ 
++	pr_warn("CPU idle is currently broken on Armada 38x: disabling");
++	return 0;
++
+ 	np = of_find_compatible_node(NULL, NULL,
+ 				     "marvell,armada-380-coherency-fabric");
+ 	if (!np)
+@@ -476,6 +479,16 @@ static int __init mvebu_v7_cpu_pm_init(v
+ 		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"))
+@@ -489,7 +502,8 @@ static int __init mvebu_v7_cpu_pm_init(v
+ 		return ret;
+ 
+ 	mvebu_v7_pmsu_enable_l2_powerdown_onidle();
+-	platform_device_register(&mvebu_v7_cpuidle_device);
++	if (mvebu_v7_cpuidle_device.name)
++		platform_device_register(&mvebu_v7_cpuidle_device);
+ 	cpu_pm_register_notifier(&mvebu_v7_cpu_pm_notifier);
+ 
+ 	return 0;