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From: robherring2@gmail.com (Rob Herring)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v3] [RFC] arm: use PSCI if available
Date: Thu, 28 Mar 2013 10:04:04 -0500	[thread overview]
Message-ID: <51545BE4.9050206@gmail.com> (raw)
In-Reply-To: <alpine.LFD.2.03.1303281048060.1372@syhkavp.arg>

On 03/28/2013 09:51 AM, Nicolas Pitre wrote:
> On Thu, 28 Mar 2013, Stefano Stabellini wrote:
> 
>> - the interface to bring up secondary cpus is different and based on
>> PSCI, in fact Xen is going to add a PSCI node to the device tree so that
>> Dom0 can use it.
>>
>> Oh wait, Dom0 is not going to use the PSCI interface even if the node is
>> present on device tree because it's going to prefer the platform smp_ops
>> instead.
> 
> Waitaminute...  I must have missed this part.
> 
> Who said platform specific methods must be used in preference to PSCI?

I did. Specifically, I said the platform should be allowed to provide
its own smp_ops. A platform may need to do addtional things on top of
PSCI for example.

> If DT does provide PSCI description, then PSCI should be used.  Doing 
> otherwise is senseless.  If PSCI is not to be used, then it should not 
> be present in DT.

You can't assume the DT and kernel are in-sync. For example, I've added
PSCI in the firmware and DTB (part of the firmware), but the highbank
kernel may or may not use it depending if I convert it.

Rob

> 
> 
> Nicolas
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
> 

WARNING: multiple messages have this Message-ID (diff)
From: Rob Herring <robherring2@gmail.com>
To: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>,
	"xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>,
	"linux@arm.linux.org.uk" <linux@arm.linux.org.uk>,
	"arnd@arndb.de" <arnd@arndb.de>,
	Marc Zyngier <Marc.Zyngier@arm.com>,
	Will Deacon <will.deacon@arm.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH v3] [RFC] arm: use PSCI if available
Date: Thu, 28 Mar 2013 10:04:04 -0500	[thread overview]
Message-ID: <51545BE4.9050206@gmail.com> (raw)
In-Reply-To: <alpine.LFD.2.03.1303281048060.1372@syhkavp.arg>

On 03/28/2013 09:51 AM, Nicolas Pitre wrote:
> On Thu, 28 Mar 2013, Stefano Stabellini wrote:
> 
>> - the interface to bring up secondary cpus is different and based on
>> PSCI, in fact Xen is going to add a PSCI node to the device tree so that
>> Dom0 can use it.
>>
>> Oh wait, Dom0 is not going to use the PSCI interface even if the node is
>> present on device tree because it's going to prefer the platform smp_ops
>> instead.
> 
> Waitaminute...  I must have missed this part.
> 
> Who said platform specific methods must be used in preference to PSCI?

I did. Specifically, I said the platform should be allowed to provide
its own smp_ops. A platform may need to do addtional things on top of
PSCI for example.

> If DT does provide PSCI description, then PSCI should be used.  Doing 
> otherwise is senseless.  If PSCI is not to be used, then it should not 
> be present in DT.

You can't assume the DT and kernel are in-sync. For example, I've added
PSCI in the firmware and DTB (part of the firmware), but the highbank
kernel may or may not use it depending if I convert it.

Rob

> 
> 
> Nicolas
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
> 


  reply	other threads:[~2013-03-28 15:04 UTC|newest]

Thread overview: 65+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-03-27 12:50 [PATCH v3] [RFC] arm: use PSCI if available Stefano Stabellini
2013-03-27 12:50 ` Stefano Stabellini
2013-03-27 12:50 ` Stefano Stabellini
2013-03-27 13:35 ` Marc Zyngier
2013-03-27 13:35   ` Marc Zyngier
2013-03-27 16:20   ` Rob Herring
2013-03-27 16:20     ` Rob Herring
2013-03-27 13:38 ` Will Deacon
2013-03-27 13:38   ` Will Deacon
2013-03-27 16:23   ` Stefano Stabellini
2013-03-27 16:23     ` Stefano Stabellini
2013-03-27 16:35     ` Rob Herring
2013-03-27 16:35       ` Rob Herring
2013-03-27 17:10       ` Stefano Stabellini
2013-03-27 17:10         ` Stefano Stabellini
2013-03-27 17:24         ` Nicolas Pitre
2013-03-27 17:24           ` Nicolas Pitre
2013-03-27 18:22           ` Stefano Stabellini
2013-03-27 18:22             ` Stefano Stabellini
2013-03-27 17:45         ` Rob Herring
2013-03-27 17:45           ` Rob Herring
2013-03-27 18:03           ` Arnd Bergmann
2013-03-27 18:03             ` Arnd Bergmann
2013-03-27 18:14             ` Stefano Stabellini
2013-03-27 18:14               ` Stefano Stabellini
2013-03-27 17:23     ` Will Deacon
2013-03-27 17:23       ` Will Deacon
2013-03-28 12:48       ` Stefano Stabellini
2013-03-28 12:48         ` Stefano Stabellini
2013-03-28 14:51         ` Nicolas Pitre
2013-03-28 14:51           ` Nicolas Pitre
2013-03-28 15:04           ` Rob Herring [this message]
2013-03-28 15:04             ` Rob Herring
2013-03-28 15:36             ` Stefano Stabellini
2013-03-28 15:36               ` Stefano Stabellini
2013-03-28 15:39             ` Nicolas Pitre
2013-03-28 15:39               ` Nicolas Pitre
2013-03-28 16:00               ` Will Deacon
2013-03-28 16:00                 ` Will Deacon
2013-03-28 16:06                 ` Nicolas Pitre
2013-03-28 16:06                   ` Nicolas Pitre
2013-03-28 16:20                 ` Stefano Stabellini
2013-03-28 16:20                   ` Stefano Stabellini
2013-03-28 18:38               ` Rob Herring
2013-03-28 18:38                 ` Rob Herring
2013-03-29 13:22                 ` Stefano Stabellini
2013-03-29 13:22                   ` Stefano Stabellini
2013-03-29 13:54                   ` Rob Herring
2013-03-29 13:54                     ` Rob Herring
2013-03-29 14:47                     ` Stefano Stabellini
2013-03-29 14:47                       ` Stefano Stabellini
2013-03-27 16:33   ` Rob Herring
2013-03-27 16:33     ` Rob Herring
2013-03-27 17:05     ` Will Deacon
2013-03-27 17:05       ` Will Deacon
2013-03-27 17:50       ` Arnd Bergmann
2013-03-27 17:50         ` Arnd Bergmann
2013-03-27 18:12         ` Will Deacon
2013-03-27 18:12           ` Will Deacon
2013-03-27 19:10           ` Rob Herring
2013-03-27 19:10             ` Rob Herring
2013-03-27 19:14           ` Arnd Bergmann
2013-03-27 19:14             ` Arnd Bergmann
2013-03-27 14:55 ` Rob Herring
2013-03-27 14:55   ` Rob Herring

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