ARM: mvebu: Disable CPU Idle on Armada 38x

commit 548ae94c1cc7fc120848757249b9a542b1080ffb upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/arm/mach-mvebu/pmsu.c b/arch/arm/mach-mvebu/pmsu.c
index d8ab605a44fa7f80a87edbd2ffeadd386903ea16..e8ba3c692527a6056bd444eaa9c0da05e06e95b8 100644 (file)
--- a/arch/arm/mach-mvebu/pmsu.c
+++ b/arch/arm/mach-mvebu/pmsu.c
@@ -415,6 +415,9 @@ static __init int armada_38x_cpuidle_init(void)
        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(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"))
@@ -489,7 +502,8 @@ static int __init mvebu_v7_cpu_pm_init(void)
                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;