Re: [PATCH RFC net-next 0/3] net: phy: sfp: Warn when using generic PHY driver

[Russell King - ARM Linux <linux@armlinux.org.uk>]

On Tue, Nov 06, 2018 at 03:38:44PM -0800, David Miller wrote:
> From: Florian Fainelli <f.fainelli@gmail.com>
> Date: Tue,  6 Nov 2018 15:29:10 -0800
> 
> > This patch series allows warning an user that the generic PHY driver(s)
> > are used when a SFP incorporates a PHY (e.g: 1000BaseT SFP) which is
> > likely not going to work at all.
> > 
> > Let me know if you would want to do that differently.
> 
> Is there ever a possibility that the generic PHY driver could work
> in an SFP situation?

I don't yet see the reason for Florian's patch series - all the Marvell
88e1111 based modules I have, or have come across in information from
manufacturers self-configure themselves and don't really need the
Marvell 1G PHY driver.

For example, the Source Photonics were offering a range of 1GbaseT
modules with the 88e1111 programmed in different modes, but published
instructions for the register accesses to configure them differently
(eg, SGMII vs 1000base-X interface facing the MAC).  Depending on
the module part number determines which mode the PHY has been
programmed to come up in.

So in theory, you don't need any PHY driver for these modules - but
it's useful to have a functional PHY driver to be able to read out
the negotiated flow control results.

I'd like more information from Florian about the reasoning behind
this patch series before it's merged.

-- 
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