Hi Thomas,
On 31/03/2015 18:04, Thomas Petazzoni wrote:
> Dear Gregory CLEMENT,
>
> On Wed, 25 Feb 2015 19:30:50 +0100, Gregory CLEMENT wrote:
>> 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@xxxxxxxxxxxxxxxxxx>
>> Cc: <stable@xxxxxxxxxxxxxxx> # v3.17 +
>
> Tested-by: Thomas Petazzoni <thomas.petazzoni@xxxxxxxxxxxxxxxxxx>
>
> I tested on Armada 38x, and indeed CPU hotplug is properly disabled,
> and it doesn't prevent suspend/resume (not supported yet in mainline,
> but hopefully soon to be supported).
Great!
>
> Some minor comments below.
>
>> diff --git a/arch/arm/mach-mvebu/pmsu.c b/arch/arm/mach-mvebu/pmsu.c
>> index 8b9f5e202ccf..2145f192662f 100644
>> --- 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");
>
> Idle -> idle
>
OK
>> + return 0;
>> +
>> np = of_find_compatible_node(NULL, NULL,
>> "marvell,armada-380-coherency-fabric");
>> if (!np)
>> @@ -469,13 +472,23 @@ static __init int armada_xp_cpuidle_init(void)
>> static int __init mvebu_v7_cpu_pm_init(void)
>> {
>> struct device_node *np;
>> - int ret;
>> + int ret = 0;
>
> Not clear why this change is needed.
It was a left over of an older version I will remove it.
>
>>
>> np = of_find_matching_node(NULL, of_pmsu_table);
>> if (!np)
>> 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");
>
> Hotplug -> hotplug.
OK
Thanks,
Gregory
--
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
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