[PATCH 1/3] Add smp support for Allwinner A20(sunxi 7i).

cinifr cinifr at gmail.com
Mon Sep 23 10:43:55 EDT 2013


> In which case this kernel patch needs instead to speak the bootloader
> wakeup protocol instead of speaking to the h/w directly like you've done
> here, right?
>
> Or is it possible for the bootloader to set these things up and then put
> the CPU back to sleep such that it both retains any settings and is
> wakable by this patch? This code contains core resets and power control,
> which makes me suspect not.

And I think secondary cpus  remains setting after h/w boot.
>> > Wouldn't it be better to do all this stuff in the bootloader and
>> either
>> > implement PSCI or have the bootloader do the traditional holding pen
>> and
>> > mbox address thing?
Uboot doesnot support PSCI, it use  traditional holding pen for sunxi
platform now.

>> >
>> I have modified uboot to set cntfrq and cntvoff in all smp cpus,and it
>> works well. I guess kernel should believe all cpu should be all same
>> when kernel boot. Bootloader should do it to ensure that.
>
> Yes, I think all CPUs must be in the same state at boot.
>
> But if you've done all that then what is this patch for?
>
> Do you have links to your u-boot patches?
>
> Ian.
Yes, This is my patch for uboot.
My working uboot code is in https://github.com/linux-sunxi/u-boot-sunxi.git
Note this is only test patch. I have not commit it  formally for uboot.

Fan
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