[linux-sunxi] Re: [PATCH v3 3/3] sunxi: add support for Lichee Pi Zero

2017-02-15 Thread Maxime Ripard 
On Thu, Feb 16, 2017 at 01:32:19AM +, André Przywara wrote:
> Whether we need PSCI on an UP system is a separate question, I don't
> know from the top of my head if ARM(32) uses it for suspend/resume. But
> anyway this is not implemented in U-Boot's PSCI implementation, IIRC.

Antoine (in CC) did this for the A13 in order to implement cpuidle.

http://lists.denx.de/pipermail/u-boot/2016-October/271038.html

So it's definitely something we can (and should) do.

Maxime

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Re: [linux-sunxi] Re: [PATCH v3 3/3] sunxi: add support for Lichee Pi Zero

2017-02-15 Thread Chen-Yu Tsai 
On Thu, Feb 16, 2017 at 9:32 AM, André Przywara  wrote:
> On 14/02/17 07:36, Maxime Ripard wrote:
>> On Mon, Feb 13, 2017 at 04:12:04PM +0800, Icenowy Zheng wrote:
>>>
>>> 2017年2月13日 15:17于 Maxime Ripard 写道：

 Hi,

 On Sat, Feb 11, 2017 at 07:11:02PM +0800, Icenowy Zheng wrote:
> @@ -0,0 +1,13 @@
> +CONFIG_ARM=y
> +CONFIG_ARCH_SUNXI=y
> +# CONFIG_ARMV7_NONSEC is not set

 Why? It doesn't have Trustzone?
>>>
>>> The CPU has Secure mode, but no TrustZone Peripheral Controller,
>>> neither SMP.
>>
>> Still, booting in HYP and having PSCI sounds like a good idea.
>
> Yes, so without this option Linux will run in secure state, if I am not
> mistaken, which is discouraged. Instead we should enter Linux in
> (non-secure) HYP mode [1], which will allow KVM, for instance. So I'd
> recommend to remove this last line.
> Whether we need PSCI on an UP system is a separate question, I don't
> know from the top of my head if ARM(32) uses it for suspend/resume. But
> anyway this is not implemented in U-Boot's PSCI implementation, IIRC.
> So for just disabling PSCI we could use:
>
> +# CONFIG_ARMV7_PSCI is not set

We'll need to add some more code (or disable some) though. If PSCI isn't
enabled, U-boot will try to bring up the cores (by calling some non-existent-
in-sunxi function) and put them in a holding pen.

I guess Icenowy can figure that bit out.

ChenYu

>
> Cheers,
> Andre.
>
> [1] http://lxr.free-electrons.com/source/Documentation/arm/Booting#L188
>
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[linux-sunxi] Re: [PATCH v3 3/3] sunxi: add support for Lichee Pi Zero

2017-02-15 Thread André Przywara 
On 14/02/17 07:36, Maxime Ripard wrote:
> On Mon, Feb 13, 2017 at 04:12:04PM +0800, Icenowy Zheng wrote:
>>
>> 2017年2月13日 15:17于 Maxime Ripard 写道：
>>>
>>> Hi, 
>>>
>>> On Sat, Feb 11, 2017 at 07:11:02PM +0800, Icenowy Zheng wrote: 
 @@ -0,0 +1,13 @@ 
 +CONFIG_ARM=y 
 +CONFIG_ARCH_SUNXI=y 
 +# CONFIG_ARMV7_NONSEC is not set 
>>>
>>> Why? It doesn't have Trustzone? 
>>
>> The CPU has Secure mode, but no TrustZone Peripheral Controller,
>> neither SMP.
> 
> Still, booting in HYP and having PSCI sounds like a good idea.

Yes, so without this option Linux will run in secure state, if I am not
mistaken, which is discouraged. Instead we should enter Linux in
(non-secure) HYP mode [1], which will allow KVM, for instance. So I'd
recommend to remove this last line.
Whether we need PSCI on an UP system is a separate question, I don't
know from the top of my head if ARM(32) uses it for suspend/resume. But
anyway this is not implemented in U-Boot's PSCI implementation, IIRC.
So for just disabling PSCI we could use:

+# CONFIG_ARMV7_PSCI is not set

Cheers,
Andre.

[1] http://lxr.free-electrons.com/source/Documentation/arm/Booting#L188

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[linux-sunxi] Re: [PATCH v3 3/3] sunxi: add support for Lichee Pi Zero

2017-02-13 Thread Maxime Ripard 
On Mon, Feb 13, 2017 at 04:12:04PM +0800, Icenowy Zheng wrote:
> 
> 2017年2月13日 15:17于 Maxime Ripard 写道：
> >
> > Hi, 
> >
> > On Sat, Feb 11, 2017 at 07:11:02PM +0800, Icenowy Zheng wrote: 
> > > @@ -0,0 +1,13 @@ 
> > > +CONFIG_ARM=y 
> > > +CONFIG_ARCH_SUNXI=y 
> > > +# CONFIG_ARMV7_NONSEC is not set 
> >
> > Why? It doesn't have Trustzone? 
> 
> The CPU has Secure mode, but no TrustZone Peripheral Controller,
> neither SMP.

Still, booting in HYP and having PSCI sounds like a good idea.

Maxime

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[linux-sunxi] Re: [PATCH v3 3/3] sunxi: add support for Lichee Pi Zero

2017-02-12 Thread Maxime Ripard 
Hi,

On Sat, Feb 11, 2017 at 07:11:02PM +0800, Icenowy Zheng wrote:
> @@ -0,0 +1,13 @@
> +CONFIG_ARM=y
> +CONFIG_ARCH_SUNXI=y
> +# CONFIG_ARMV7_NONSEC is not set

Why? It doesn't have Trustzone?

Thanks,
Maxime

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Maxime Ripard, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

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