Hi Jan,

On Sun, Nov 09, 2014 at 08:35:49PM +0100, Jan Kiszka wrote:
> did anyone already happen to look into enabling CPU hotplug for the
> Allwinner A20 in upstream? I'm currently running the sunxi-next branch
> on Banana Pi, and echo 0 > .../cpu1/online just hangs the system. The
> old 3.4 LeMaker kernel works fine in this regard. I can try to look into
> details and port things over, just want to avoid duplicate efforts.

Having hotplug support would indeed be very welcome.

However, it should be done in u-boot, through PSCI, and not in the
kernel itself.

As far as I'm aware, no one worked actively on it, beside some WIP
commit from Marc a while ago:
https://git.kernel.org/cgit/linux/kernel/git/maz/u-boot.git/commit/?h=wip/psci&id=45379c0f9cf812f0f62722f4015ec907fa5dc144

Maxime

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