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

[Yingjoe Chen]

On Wed, 2015-05-06 at 13:04 +0200, Matthias Brugger wrote:
> Hi Joe,
> 
> 2015-05-06 10:29 GMT+02:00 Matthias Brugger <matthias.bgg at gmail.com>:
> > 2015-05-06 9:59 GMT+02:00 Yingjoe Chen <yingjoe.chen at mediatek.com>:
> >> 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.
> 

Hi Matthias,

Unfortunately I can't reproduce or figure out why this could happen.
I change to use common kernel code secondary_startup_arm in new series,
could you that a try?
Thanks.

Joe.C