On 2/16/23 19:54, Andrew Lunn wrote:
I gave "rgmii-id" a try and it's not usable, I get too many errors. So
"rgmii" should be the right choice here.
I would actually say it shows we don't understand what is going on
with delays. "rgmii" is not every often the correct value. The fact it
works suggests the MAC is adding delays.
What value are you using for starfive,gtxclk-dlychain ?
This is set to '4' in patch 12/12.
Try 0 and then "rgmii-id"
I made some more tests and it seems the only stable configuration is
"rgmii" with "starfive,gtxclk-dlychain" set to 4:
phy-mode | dlychain | status
---------+----------+--------------------------------------------
rgmii | 4 | OK (no issues observed)
rgmii-id | 4 | BROKEN (errors reported [1])
rgmii | 0 | UNRELIABLE (no errors, but frequent stalls)
rgmii-id | 0 | BROKEN (errors reported)
[1] Reported errors in case of BROKEN status:
$ grep '' /sys/class/net/eth0/statistics/* | grep -v ':0$'
/sys/class/net/eth0/statistics/rx_crc_errors:6
/sys/class/net/eth0/statistics/rx_errors:6
/sys/class/net/eth0/statistics/tx_bytes:10836
/sys/class/net/eth0/statistics/tx_packets:46
Andrew
