Messages in this thread | | | Date | Mon, 23 Sep 2013 21:34:30 +0300 | From | "" <> | Subject | Re: [PATCH 1/3] Add smp support for Allwinner A20(sunxi 7i). |
| |
Hi,
On Mon, Sep 23, 2013 at 10:43:55PM +0800, cinifr wrote: > > 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.
Please do so. I'd like very much to avoid ending up in a situation where we would break the mainline kernel for the A20, without any bootloader we can point the users to to fix the issues.
Maxime
-- Maxime Ripard, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com [unhandled content-type:application/pgp-signature] | |