[PATCH 21/21] ARM: Kirkwood: Remove DT support

From: ijc@hellion.org.uk (Ian Campbell)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 21/21] ARM: Kirkwood: Remove DT support
Date: Thu, 20 Feb 2014 12:51:04 +0000	[thread overview]
Message-ID: <1392900664.23342.60.camel@kazak.uk.xensource.com> (raw)
In-Reply-To: <20140220121821.GO11878@lunn.ch>

On Thu, 2014-02-20 at 13:18 +0100, Andrew Lunn wrote:
> On Thu, Feb 20, 2014 at 11:34:36AM +0000, Ian Campbell wrote:
> > (adding debian-arm/-kernel)
> > On Thu, 2014-02-20 at 11:58 +0100, Andrew Lunn wrote:
> > > On Thu, Feb 20, 2014 at 10:30:17AM +0000, Ian Campbell wrote:
> > > > On Fri, 2014-02-07 at 18:34 +0100, Sebastian Hesselbarth wrote:
> > > > > On 02/07/2014 12:42 AM, Andrew Lunn wrote:
> > > > > > Now that all the device tree support is in mach-mvebu, remove it from
> > > > > > mach-kirkwood.
> > > > > >
> > > > > > Regenerate kirkwood_defconfig, removing all DT support, and a couple
> > > > 
> > > > s/DT/board-file/?
> > > 
> > > We keep any system using -setup.c files, and remove the ability to
> > > boot systems with a DT description. Thus mach-kirkwood becomes legacy,
> > > and you should now be trying to only use mach-mvebu, compiled for v5
> > > systems and a second compile for v7 systems.
> > 
> > Just to check I've got it: The majority of the systems previously
> > supported by mach-kirkwood (either board file or DTB based) are now
> > supported by mach-mvebu.
> 
> We plan to move all kirkwood systems which are DT to mach-mvebu. Any
> systems which are not DT will get left in mach-kirkwood.
> 
> What would be interesting to know is, if any of the systems left
> behind are supported by debian. So LaCie 2Big and 5Big, HP t5325 thin
> client and Marvell OpenRD machines? If you don't support any of these,
> you can drop mach-kirkwood.
> 
> > Is it possible to have both ARCH_KIRKWOOD and ARCH_MVEBU in the same
> > v5 .config?
> 
> Armada XP, 370, and the new SoCs going in this cycle all use ARM v7
> CPUs. Dove also uses an ARM v7 cpu and we intent to move it from
> mach-dove into mach-mvebu.
> 
> Now ARM v7 cpu and ARM v5 CPUs are mutually incompatible. You cannot
> combine them into one kernel. Do you currently build mach-mvebu as
> part of a multi v7 kernel. That is, you have one kernel which boots on
> all v7 machines?

Debian has a single v7 flavour, armmp which uses the multi platform
stuff. (actually there is a second armmp-lpae, but lets ignore that)

I'm only really concerned about the v5 stuff here. Debian has multiple
v5 flavours: ixp4xx, kirkwood, mv78xx0, orion5x and versatile.

> What this patchset does is also make mach-mvebu part of the multi v5
> kernel. So you just need one kernel for all ARM v5 machines which are
> part of multi v5. The long term goal is that you need just two 32 ARM
> kernels, multi v5 and multi v7. However orion5x and mv76xx0 are not
> yet part of theses, so we are not there yet.

So in answer to my question, on v5 ARCH_KIRKWOOD and ARCH_MVEBU *cannot*
coexist in the same binary?

> > IOW that all of the platforms currently supported by the
> > Debian kirkwood flavour remain supportable in the same binary after this
> > change. It looks like it should be to me, but I'm not 100% sure.
> 
> If you don't support LaCie 2Big and 5Big, HP t5325 thin client and
> Marvell OpenRD then yes, you have one binary. That binary could
> potentially support over v5 machines, but i have no idea what ARM
> machines Debian actually supports. Is there a list somewhere?

http://anonscm.debian.org/gitweb/?p=d-i/flash-kernel.git;a=blob;f=db/all.db;h=fab340782c783c4f8a172f0424a791037dee90cf;hb=HEAD is a reasonable approximation for what is supported, at least in a well integrated way. I can see all of the LaCie systems, t5325 and openrd stuff which you mention in that list.

http://anonscm.debian.org/viewvc/kernel/dists/trunk/linux/debian/config/armel/config.kirkwood?revision=20912&view=markup
is the kirkwood specific kernel config s/trunk/wheezy/ if you want to
see the current stable version. Other config.* for other flavours.

I'm only concerned with the impact of these changes on the kirkwood
flavour right now, I don't want to confuse the matter by considering the
possibility of consolidating flavours.

Ian.

>  
> > Is there a tree I can pull to see what is going into v3.15 in this
> > area?
> 
> At the moment there is not a tree with all the different parts.  I
> have a tree with these specific patches. There are other trees which
> contain new DT descriptions for new devices, like Bubba B3, and
> systems which have been converted to DT, like the QNAP T4xx.
> 
> > > My aim is 3.15. Most patches have been Acked now, so i think we are on
> > > track for that.
> > 
> > If kirkwood and mvebu are mutually exclusive on v5 then this sounds like
> > it might end up being more complicated than just setting Append-DTB-From
> > in the flash-kernel db. In that case if we could hold off on pulling the
> > existing kirkwood support until there is a transition plan here I'd be
> > very grateful.
> 
> Lets make sure we are all on the same page with v5, v7, kirkwood,
> mvebu, multi, and what kernels Debian currently builds and how
> flash-kernel works etc. We can then discuss transition plans.
> 
>      Andrew
> 