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From: jan.kiszka@web.de (Jan Kiszka)
To: linux-arm-kernel@lists.infradead.org
Subject: AMR: sun7i: CPU hotplug support?
Date: Mon, 10 Nov 2014 07:03:54 +0100	[thread overview]
Message-ID: <5460554A.1060701@web.de> (raw)
In-Reply-To: <20141109231744.GC2989@lukather>

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.

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WARNING: multiple messages have this Message-ID (diff)
From: Jan Kiszka <jan.kiszka@web.de>
To: Maxime Ripard <maxime.ripard@free-electrons.com>,
	Marc Zyngier <marc.zyngier@arm.com>
Cc: linux-arm-kernel@lists.infradead.org,
	linux-sunxi@googlegroups.com,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: AMR: sun7i: CPU hotplug support?
Date: Mon, 10 Nov 2014 07:03:54 +0100	[thread overview]
Message-ID: <5460554A.1060701@web.de> (raw)
In-Reply-To: <20141109231744.GC2989@lukather>

[-- Attachment #1: Type: text/plain, Size: 1345 bytes --]

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.


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  reply	other threads:[~2014-11-10  6:03 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-11-09 19:35 AMR: sun7i: CPU hotplug support? Jan Kiszka
2014-11-09 19:35 ` Jan Kiszka
2014-11-09 23:17 ` Maxime Ripard
2014-11-09 23:17   ` Maxime Ripard
2014-11-10  6:03   ` Jan Kiszka [this message]
2014-11-10  6:03     ` Jan Kiszka
2014-11-10  8:25     ` Jan Kiszka
2014-11-10  8:25       ` Jan Kiszka
2014-11-10  9:17       ` Marc Zyngier
2014-11-10  9:17         ` Marc Zyngier
2014-11-10  9:36         ` Jan Kiszka
2014-11-10  9:36           ` Jan Kiszka
2014-11-10  9:52           ` Marc Zyngier
2014-11-10  9:52             ` Marc Zyngier
2014-11-10 10:33             ` Jan Kiszka
2014-11-10 10:33               ` Jan Kiszka
2014-11-10 11:07               ` Marc Zyngier
2014-11-10 11:07                 ` Marc Zyngier

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