quoted

You configure the PHY to support downshift. If it has performed a
downshift, does it report the actual speed in the usual registers
read
by genphy_read_status(), or is it necessary to read a vendor
register?
From the tests I've done, I got the actual speed read correctly by

genphy_read_status function.
I did a test by adding in this function the vendor register reading at
the same time and comparing it and did not get a discrepancy too when
switching with ethtool between different speed configurations.

Would it be more reliable to use the vendor register instead?

It is unusual to report the actually speed in BMSR etc, which is why i
asked. But if it works, this is fine.

       Andrew