From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: [net-next.git 0/9] stmmac: update to March_2013 (adding PTP &
 RGMII/SGMII)
Date: Thu, 07 Mar 2013 15:34:56 -0500 (EST)
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From: Giuseppe CAVALLARO <peppe.cavallaro@st.com>
Date: Thu,  7 Mar 2013 11:50:10 +0100

> The PTP support is quite intrusive because it needs to support the extended
> descriptors used for saving the HW timestamps.
> These are available in new chip generations, only.
> So we have actually found useful to use some Kconfig options to
> surround PTP and extended descriptor support. This approach helped on
> old platform (embeeded system) where PTP is not supported and where we
> do not want to pay extra code and check in critical rx/tx paths.

I would prefer run time handling of all of this.

You do not need to put extra checks in the fast paths, instead you
have different methods that get hooked up into the netdev_ops
based upon chip capabilities/features/mode.

Thanks.