Re: How to operate 10Gbit SFP+ module if driver doesn't support SFP+?

[Andrew Lunn <andrew@lunn.ch>]

On Fri, Apr 24, 2020 at 06:41:18PM +0200, Tanjeff Moos wrote:
> Hello netdev list,
> 
> I hope that I'm at the right mailinglist for my question. If not, let me
> know.
> 
> 
> Abstract
> --------
> 
> I'm trying to get a 10GBASE-SR SFP+ module running on a self-made board.
> The MAC driver doesn't support phylink (i.e. no I²C accesses to the SFP+
> registers), therefore I want to use PHY-less mode. On the other hand,
> the "fixed-link" mode supports only up to 1 Gbit. The "in-band-status"
> mode is said to not work with my setup. Thus I'm running out of options.
> I ask you if there are further options to get things running.
> 
> 
> About the hardware
> ------------------
> 
> My company built an access point containing an NXP QorIQ T1023 Soc. This
> SoC includes a MAC which is connected to an SFP+ cage. We use XFI for
> the connection between MAC and SFP+. In addition, the SFP+ module is
> connected to the SoC via I²C to access its registers.
> 
> 
> About the software
> ------------------
> 
> I am running OpenWRT with a Linux 4.14.137 kernel. There are patches on
> that kernel (mostly from the OpenWRT project, some by us).
 
Hi Tanjeff

Most kernel hackers don't care about such old kernels.

> Details about the problem
> -------------------------
> 
> For the MAC, I use the DPAA driver.

Is this dpaa2? If so, a modern kernel supports PHYLINK. That solves
most of your problems. The kernel SFP code should work so long as you
have access the i2c via a standard linux I2C bus.

     Andrew