Re: [Intel-wired-lan] [PATCH] e1000e: Link flap workaround option for false IRP events

From: Andrew Lunn
Date: Tue Mar 04 2025 - 17:25:25 EST


> > I suggest to try replacing the register read for a short delay or
> > reading the PHY STATUS register instead.
> >
>
> Ack - we'll try that, and collect some other debug registers in the process.
> Will update with findings - this may take a while :)

Please be careful with which register you choice. Because the link
status bit in BMSR is latching, you should not be reading it and
discarding the result.

Reading register 2 or 3 should be totally safe.

Another thing to keep in mind, you cannot unconditionally read a paged
register in this particular PHY, because the e1000e is used with a
number of different PHYs. That register does not exist in other PHYs,
and the action of selecting the page performs a register write, which
for some other PHY could be destructive. So i would suggest you keep
to registers defined in 802.3 C22.

Andrew