From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: [PATCH v2] sh_eth: use RNC mode for R8A7790/R87791
Date: Mon, 02 Jun 2014 13:49:15 -0700 (PDT)
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From: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Date: Mon, 02 Jun 2014 23:33:47 +0400

>    Looks like the early SH2/3 SoCs didn't implement the whole register.
> Despite that, sh_eth_dev_init() always writes to this register... :-/
> So far, the RMCR.RNC bit was mostly set for the Gigabit-capable
> controllers, however that rule wasn't strictly followed. Well, this
> driver is still a mess, and it's hard to deal with it without the
> necessary documentation.

Why don't we therefore:

1) Skip the register write if the per-chip value is zero.

2) Add the RNC bit to all of the gigabit capable controllers.