On Thu, 29 Oct 2020 13:38:00 +0000
Russell King - ARM Linux admin [off-list ref] wrote:

Any ideas why it takes 25 seconds for the module to initialise - the
88x3310 startup is pretty fast in itself. However, it never amazes me
how broken SFP modules can be.

I don't know, but for the first 25 seconds the SFP returns 0xffff on
all reads. I think it is due to the internal MCU doing it's own stuff
with the PHY during that time.

Marek