Re: [PATCH net-next] net: phy: micrel: Adding SQI support for lan8814 phy

quoted

quoted

In lan8814 phy only channel 0 is used for 100base-tx. So returning SQI
value for channel 0.

What if the other pairs are bad? Maybe Oleksij has an opinion here.

Also 100baseTX (and 10baseT) has two pairs, one for transmitting and one
for receiving. I guess you meassure the SQI on the receiving side. So is
channel 0 correct here?

Again this is the first time I hear about SQI but it puzzles me that
it only evaluate one pair in this case. So as a user who reads this
SQI might be misleaded.

Wow! I was so possessed with one-pair networks, that forgot to image
that there is 1000Base-T with more then one pairs :D

Yes, your are right. We wont to have readings from all RX channels and
be able to export them to the user space. In fact, if i see it
correctly, the LAN8814_DCQ_CTRL_CHANNEL_MASK value should be synced with
the MDI-X state. Otherwise we will be reading TX channels.

I don't know if i should trust the datasheet i found, but it suggests
the register in MMD device 1 space has a field to indicate which cable
pair should be measured. So for 1000Base-T all pairs are both Rx and
Tx, so i would expect 4 values are returned. That then might need an
uAPI extension, if you were focused on T1 :-)

    Andrew