From mboxrd@z Thu Jan  1 00:00:00 1970
From: Simon Horman <horms@verge.net.au>
Date: Mon, 06 Jan 2014 02:24:30 +0000
Subject: Re: [PATCH 3/3] ARM: shmobile: Koelsch: Add QSPI support
Message-Id: <20140106022426.GD11231@verge.net.au>
List-Id: <linux-sh.vger.kernel.org>
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 <52C6EAA7.7050200@cogentembedded.com>
 <CAMuHMdVzawC2ccXCwyLSe7u0Uaa0qpLwaO+3dqQiSrmOcGdTCA@mail.gmail.com>
 <871u0mkkpg.wl%kuninori.morimoto.gx@gmail.com>
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To: linux-arm-kernel@lists.infradead.org

On Sun, Jan 05, 2014 at 04:39:14PM -0800, Kuninori Morimoto wrote:
> Hi
> 
> > <sergei.shtylyov@cogentembedded.com> wrote:
> > >> +       platform_device_register_resndata(&platform_bus, "qspi", 0,
> > >
> > >    As I understood, there's single QSPI controller, so why you pass 0, and
> > > not -1 here?
> > 
> > Indeed, there's only a single QSPI instance.
> > However, I choose to use "0" for consistency with Lager.
> > Mach-shmobile seems to use a mix of 0 and -1.
> > 
> > If the maintainer prefers -1, I can change that.
> 
> In SPI driver case, spi master will use dynamic 
> bus_num value if ID was -1 (in spi_register_master()).
> Then, slave device can't be detected.
> So, ID = 0 is reasonable even though single QSPI.

When it makes sense I prefer -1, however, in this case it
seems that 0 is a better choice.