AM5728: PRU Ethernet 10Mbps issue

Hi,

My customer reported PRU Ethernet does not work with 10M operation.
Customer’s environments are below:
device : AM5728
board : custom board
SW : ti-rt-linux-4.4.144-rt161 with modification(*)

(*): Customer once used prueth driver included in PROCESSOR-SDK-LINUX-RT-AM57X 03.03.00.04,
but the driver could not get PHY registers’ values.
So customer ported prueth driver/firmware from PROCESSOR-SDK-LINUX-RT-AM57X 05.03.00.07
to ti-rt-linux-4.4.144-rt161

Issue details:
When 10M ethernet connection is established, PING fails with ETH1/2(PRU ports).
Using ETH3(GMAC port) is ok, PING passes.
100M configuration is OK for all cases(ETH1/2/3).
With 10M configuration, when PING is sent from the device to PC,
“APR request from the device to PC” and “APR response from PC to the device” are monitored by wireshark.

Customer also checked PRU interrupt counter and found only tx counter was incremented, but rx counter did not.
It seems PRU could not detect receiving packets.

Customer checked the same test on AM572x IDK (with SDK 05.03.00.07), it works fine(PING passes)
and both tx/rx counters are incremented.
Customer uses different PHY device(Microchip: LAN8710A) on their custom board.
PHY status is checked by polling on their board. (On IDK, interrupts are used for PHY status update).

Are there any points customer should check?
Any advices would be helpful.

Thanks and regards,
Koichiro Tashiro