RE: [WARNING: ATTACHMENT UNSCANNED]Re: [PATCH RFC net-next 1/2] net: pcs: xpcs: Add special code to operate in Microchip KSZ9477 switch

[Jose Abreu]

From: Russell King (Oracle) <linux@xxxxxxxxxxxxxxx>
Date: Thu, Jan 30, 2025 at 11:02:00

> Would it be safe to set these two bits with newer XPCS hardware when
> programming it for 1000base-X mode, even though documentation e.g.
> for SJA1105 suggests that these bits do not apply when operating in
> 1000base-X mode?

It's hard to provide a clear answer because our products can all be modified
by final customer. I hope this snippet below can help:

"Nothing has changed in "AN control register" ever since at least for a decade.
Having said that, bit[4] and bit[3] are valid for SGMII mode and not valid
for 1000BASE-X mode (I don't know why customer says 'serdes' mode.
There is no such mode in ethernet standard). So, customer shall
leave this bits at default value of 0.  Even if they set to 1, there is no
impact (as those bits are not used in 1000BASE-X mode)."

Thanks,
Jose