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Date:   Sun, 30 Dec 2018 18:26:40 +1100 (AEDT)
From:   Finn Thain <fthain@telegraphics.com.au>
To:     Arnd Bergmann <arnd@arndb.de>
cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Geert Uytterhoeven <geert@linux-m68k.org>,
        Joshua Thompson <funaho@jurai.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        linux-m68k <linux-m68k@lists.linux-m68k.org>,
        linuxppc-dev <linuxppc-dev@lists.ozlabs.org>
Subject: Re: [PATCH v8 13/25] m68k: Dispatch nvram_ops calls to Atari or Mac
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On Sat, 29 Dec 2018, Arnd Bergmann wrote:

> On Wed, Dec 26, 2018 at 1:43 AM Finn Thain <fthain@telegraphics.com.au> wrote:
> 
> > +
> > +static ssize_t m68k_nvram_get_size(void)
> > +{
> > +       if (MACH_IS_ATARI)
> > +               return atari_nvram_get_size();
> > +       else if (MACH_IS_MAC)
> > +               return mac_pram_get_size();
> > +       return -ENODEV;
> > +}
> > +
> > +/* Atari device drivers call .read (to get checksum validation) whereas
> > + * Mac and PowerMac device drivers just use .read_byte.
> > + */
> > +const struct nvram_ops arch_nvram_ops = {
> > +#ifdef CONFIG_MAC
> > +       .read_byte      = m68k_nvram_read_byte,
> > +       .write_byte     = m68k_nvram_write_byte,
> > +#endif
> > +#ifdef CONFIG_ATARI
> > +       .read           = m68k_nvram_read,
> > +       .write          = m68k_nvram_write,
> > +       .set_checksum   = m68k_nvram_set_checksum,
> > +       .initialize     = m68k_nvram_initialize,
> > +#endif
> > +       .get_size       = m68k_nvram_get_size,
> > +};
> > +EXPORT_SYMBOL(arch_nvram_ops);
> 
> Since the operations are almost entirely distinct, why not have two
> separate 'nvram_ops' instances here that each refer to just
> the set they actually need?
> 

The reason for that is that I am alergic to code duplication. But I'll 
change it if you think it matters. BTW, this patch has already been acked 
by Geert.

> I was actually expecting one more patch here that would make the
> arch_nvram_ops a pointer to one of multiple structures, which would
> be easier to do with multiple copies, but I suppose there is no need
> for that here (there might be on ppc, I have to look again).
> 

Yes, I considered that too. I picked the variation that makes everything 
const.

-- 

>        Arnd
>