From: Arnd Bergmann <arnd@arndb.de>
To: linux-arm-kernel@lists.infradead.org
Cc: "alsa-devel@alsa-project.org" <alsa-devel@alsa-project.org>,
Mark Brown <broonie@opensource.wolfsonmicro.com>,
"davinci-linux-open-source@linux.davincidsp.com"
<davinci-linux-open-source@linux.davincidsp.com>,
Vaibhav Hiremath <hvaibhav@ti.com>,
"Hebbar, Gururaja" <gururaja.hebbar@ti.com>,
"alsa-user@lists.sourceforge.net"
<alsa-user@lists.sourceforge.net>, "Girdwood, Liam" <lrg@ti.com>
Subject: Re: How to handle parameter variation across different boards but same platform
Date: Thu, 5 Jul 2012 08:32:16 +0000 [thread overview]
Message-ID: <201207050832.16750.arnd@arndb.de> (raw)
In-Reply-To: <4FF52948.6090904@ti.com>
On Thursday 05 July 2012, Vaibhav Hiremath wrote:
> On 7/4/2012 7:57 PM, Mark Brown wrote:
> > On Wed, Jul 04, 2012 at 02:17:48PM +0000, Hebbar, Gururaja wrote:
> >> On Wed, Jul 04, 2012 at 19:31:18, Mark Brown wrote:
> >
> >>> If these are totally different boards they should have different machine
> >>> IDs set so machine_is_() should identify. If that isn't there then you
> >>> need to do something custom to your products to identify the boards
> >>> further.
> >
> >> They are different boards with same SoC (AM33xx). So they both are true for
> >> machine_is_am33xx().
> >
>
> What if the device only supports Linux boot from DT, where we set
> machine_desc.nr = ~0 ??
>
> Does machine ID still gets set? May be I am missing something...
No, it doesn't.
> As part of my debugging, on AM335xEVM platform machine_is_am33xx()
> returns false, since the value of machine_desc.nr is set to ~0.
Correct. However, when you are booting using the device tree, parameters
such as the clock frequency of a device should be encoded in the device
tree itself, so you don't need to know which machine you are on.
Arnd
WARNING: multiple messages have this Message-ID (diff)
From: arnd@arndb.de (Arnd Bergmann)
To: linux-arm-kernel@lists.infradead.org
Subject: How to handle parameter variation across different boards but same platform
Date: Thu, 5 Jul 2012 08:32:16 +0000 [thread overview]
Message-ID: <201207050832.16750.arnd@arndb.de> (raw)
In-Reply-To: <4FF52948.6090904@ti.com>
On Thursday 05 July 2012, Vaibhav Hiremath wrote:
> On 7/4/2012 7:57 PM, Mark Brown wrote:
> > On Wed, Jul 04, 2012 at 02:17:48PM +0000, Hebbar, Gururaja wrote:
> >> On Wed, Jul 04, 2012 at 19:31:18, Mark Brown wrote:
> >
> >>> If these are totally different boards they should have different machine
> >>> IDs set so machine_is_() should identify. If that isn't there then you
> >>> need to do something custom to your products to identify the boards
> >>> further.
> >
> >> They are different boards with same SoC (AM33xx). So they both are true for
> >> machine_is_am33xx().
> >
>
> What if the device only supports Linux boot from DT, where we set
> machine_desc.nr = ~0 ??
>
> Does machine ID still gets set? May be I am missing something...
No, it doesn't.
> As part of my debugging, on AM335xEVM platform machine_is_am33xx()
> returns false, since the value of machine_desc.nr is set to ~0.
Correct. However, when you are booting using the device tree, parameters
such as the clock frequency of a device should be encoded in the device
tree itself, so you don't need to know which machine you are on.
Arnd
next prev parent reply other threads:[~2012-07-05 8:32 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-07-04 12:45 How to handle parameter variation across different boards but same platform Hebbar, Gururaja
2012-07-04 12:45 ` Hebbar, Gururaja
2012-07-04 13:17 ` Mark Brown
2012-07-04 13:17 ` Mark Brown
2012-07-04 13:43 ` Hebbar, Gururaja
2012-07-04 13:43 ` Hebbar, Gururaja
2012-07-04 14:01 ` Mark Brown
2012-07-04 14:01 ` Mark Brown
2012-07-04 14:17 ` Hebbar, Gururaja
2012-07-04 14:17 ` Hebbar, Gururaja
2012-07-04 14:27 ` Mark Brown
2012-07-04 14:27 ` Mark Brown
[not found] ` <20120704142745.GC4111-yzvPICuk2AATkU/dhu1WVueM+bqZidxxQQ4Iyu8u01E@public.gmane.org>
2012-07-05 5:42 ` Vaibhav Hiremath
2012-07-05 5:42 ` Vaibhav Hiremath
2012-07-05 8:32 ` Arnd Bergmann [this message]
2012-07-05 8:32 ` Arnd Bergmann
2012-07-05 9:38 ` Mark Brown
2012-07-05 9:38 ` Mark Brown
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