Re: [PATCH net-next 2/2] net: sfp: enhance quirk for Fibrestore 2.5G copper SFP module

["Marek Behún" <kabel@kernel.org>]

On Tue, 23 Apr 2024 10:51:09 +0200
Eric Woudstra <ericwouds@gmail.com> wrote:

> On 4/23/24 10:40, Marek Behún wrote:
> 
> >>
> >> Also any code I found for the yt8821 is C22 only. And even more, even
> >> though we are facing with an almost similar MCU, RollBall protocol does
> >> not work. I think it is almost the same mcu, as it responds to the same
> >> eeprom password, and also the rollball password does something, but not
> >> give the expected result.
> >>  
> > 
> > What about I2C address 0x56?
> > 
> > I noticed that the Fibrestore FS SFP-2.5G-T with the realtek chip
> > also exposes clause 22 registers, but the current mdio-i2c driver wont
> > work, because the module implements the access in an incompatible way
> > (we would need to extend mdio-i2c).
> > 
> > Eric, can you check whether the motorcomm module exposes something on
> > address 0x56? With i2cdump, i.e. on omnia:
> >   i2cdump -y 5 0x56
> > (you will need to change 5 to the i2c controller of the sfp cage).
> > What does it print?
> > 
> > Marek  
> 
> The device at 0x56 is not up at the time the eeprom is checked and read.
> So when it is time to decide whether to use RollBall protocol or not,
> the data at 0x56 cannot be used.

The fixup function for those modules could enable the module and wait
for the 0x56 i2c address...

> We have more info on i2cdumps on the BPI forum (rtl8221b topic and
> yt8821 topic).