Hi,
We have used KSZ9477 chip on our i.MX8M Plus platform based custom board.
We have interfaced KSZ9477 with FEC (freescale) MAC through RGMII.
We have integrated the driver for KSZ9477 switch from
https://github.com/Microchip-Ethernet/EVB-KSZ9477/tree/master/KSZ/linux-drivers/ksz9897/linux-5.3/dr... for micrel and Freescale.
By default, KSZ9477 chip is configured to 1gbps speed. And we are able to ping the device when the link speed is 1gbps.
But we are not able to ping when the link speed changes to 100mbps. In this scenario, we observed that
for 1 gbps speed, RX clock is 125 MHz and TX Clock is 125 MHz.
But for 100mbps, the RX Clock is 125MHz but TX Clock chnages to 25 MHz.
Due to this ping doesn't work.
For this to work, we have to change the KSZ9477 speed to 100 mbps.
So, it seems to be issue with FEC controller which is not able to set the TX clock to fixed 125MHz.
We have not observed this behaviour with STMMAC Controller interfaced to KSZ9897 on i.MX8MP.
and also with FEC Controller in i.MX6sx interfaced to KSZ9477.
Can you please help with this?
Thanks,
Shivani Patel
