Re: [PATCH 0/7] Add SMP bringup support for mt65xx socs

[Matthias Brugger]

Hi Joe,

2015-05-06 10:29 GMT+02:00 Matthias Brugger <matthias.bgg@xxxxxxxxx>:
> 2015-05-06 9:59 GMT+02:00 Yingjoe Chen <yingjoe.chen@xxxxxxxxxxxx>:
>> On Wed, 2015-05-06 at 15:19 +0800, Yingjoe Chen wrote:
>>> Hi Matthias,
>> <...>
>>> > I tried on the mt8135 eval board but it fails to bring up the CPU.
>>> >
>>> > When booting:
>>> > [    1.048588] CPU1: failed to come online
>>> > [    2.049914] CPU2: failed to come online
>>> > [    3.051245] CPU3: failed to come online
>>>
>>>
>>> Thanks for testing, and the config file you provided.
>>> It seems you are running THUMB2 kernel, unfortunately mt8135 trustzone
>>> firmware doesn't support jump to THUMB2 code directly.
>>>
>>> I can workaround this with the following patch. I'll include it in my
>>> next round.
>>>
>>> Joe.C
>>>
>>> -----8<----------------
>>> diff --git a/arch/arm/mach-mediatek/platsmp.c
>>> b/arch/arm/mach-mediatek/platsmp.c
>>> index e266b3d..5dea55a 100644
>>> --- a/arch/arm/mach-mediatek/platsmp.c
>>> +++ b/arch/arm/mach-mediatek/platsmp.c
>>> @@ -57,6 +57,18 @@ static const struct of_device_id mtk_smp_boot_infos[]
>>> __initconst = {
>>>  static void __iomem *mtk_smp_base;
>>>  static const struct mtk_smp_boot_info *mtk_smp_info;
>>>
>>> +#ifdef CONFIG_THUMB2_KERNEL
>>> +__asm__(
>>> +     ".arm\n"
>>> +     "mtk_secondary_startup_fixup:\n"
>>> +     "       b secondary_startup\n"
>>> +     ".thumb\n"
>>> +);
>>> +
>>> +void mtk_secondary_startup_fixup(void);
>>> +#define secondary_startup mtk_secondary_startup_fixup
>>> +#endif
>>
>>
>> Replying myself.
>>
>> It seems kernel already have secondary_startup_arm which support this
>> usage. I'll use that in my next version instead.
>
> With this I was able to get the board up and running. I will try mt6589 ASAP.

I just realized, that your aforementioned patch for the THUMB2 kernel
breaks SMP on mt6589. Strangely without this patch it works fine.

Regrads,
Matthias

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