From mboxrd@z Thu Jan 1 00:00:00 1970 From: jan.kiszka@web.de (Jan Kiszka) Date: Mon, 10 Nov 2014 07:03:54 +0100 Subject: AMR: sun7i: CPU hotplug support? In-Reply-To: <20141109231744.GC2989@lukather> References: <545FC215.7010802@web.de> <20141109231744.GC2989@lukather> Message-ID: <5460554A.1060701@web.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 2014-11-10 00:17, Maxime Ripard wrote: > 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 OK - I guess I will need a little guidance in then: Is there a good reference board to study and to derive from? And maybe also: What is missing or not working in that u-boot branch? If I get this interface right, I just takes some device tree bits to enable this for the kernel afterward, correct? Thanks, Jan PS: That the GMAC on B-Pi has some TX reliability issues, both with kernel and u-boot, is known, right? If not, I'll open a separate thread. -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 198 bytes Desc: OpenPGP digital signature URL: