DM8107 EMAC0 Interface not working in RGMII mode

Faiyaz Pisuwala

Hi,

We have a design which configures DM8107's EMAC0 interface in RGMII mode. We have connected this RGMII interface to KSZ9031RNX Gigabit Ethernet PHY.

- We are able to communicate with KSZ9031 device via MDIO interface successfully. and we get correct link status, speed details as well after connecting to external network.

- When we run "DHCP" to get an IP address automatically for our board; we get correct speed clock waveforms as per link on both TX and RX clock signals, we are also able to see some data on RX data signals; but we do not get any data on TX data signals as well as TX_EN signal of this interface. Due to this, the Ethernet port does not work.

- We have also checked and verified Pin muxing control for this interface, boot mode settings related to EMAC0, driver software configurations related to EMAC0 interface; and all of them seem to be fine.

We are not able to understand this behavior of the RGMII interface. Can somebody please throw some light on this?

Thanks & regards

Faiyaz Pisuwala

over 12 years ago

0 Michael Po over 12 years ago

Intellectual 290 points

I have exactly the same problem, with the same PHY. I tripped checked the clocking (the clocking schematic mentions the SATA serdes and the PCI-E, it appears that you can run from just the 20mhz external clock)

The pinmux is correct, and configured in RGMII, the PHY is happy, and lock itself at 1000Mb/s everytime, but no packets get transmitted, the TX_EN pin stays low. The DMA drive in u-boot seems to go thru the motion of sending packets and clearing them from the queue, but nothing happend.

If I boot a kernel, it's the same. I get a link, and no data transmission either...

0 Michael Po over 12 years ago in reply to Michael Po

Intellectual 290 points

BTW I no not initialize pcie, and configures the SATA serdes as using the 20mhz clock (not the 100mhz). I duplicated these settings in the kernel as well, so both u-boot and the kernel should work, AFAIK... but no cigar.

Could there be an incompatibility wth that PHY series? anyone else use them?

0 Michael Po over 12 years ago in reply to Michael Po

Intellectual 290 points

bump. Anyone has a solution for this, or a hint on where to look?

0 Thiago Marques over 12 years ago

Prodigy 90 points

I have the same problem. Anyone has a solution for this, or a hint on where to look?

0 Faizel over 12 years ago in reply to Thiago Marques

Expert 1460 points

Hi,

We faced the same issue on RX path, our transmit path was OK. We got it resolved by enabling the internal delay in GMII_SEL register. I think you need to check the status of internal delay in 8107 to match the device. Try Enable/Disable the same.

Regards

Faizel

0 Mercadier Nicolas over 10 years ago in reply to Faizel

Intellectual 930 points

Hi,

I have the same issue.

How have you resolved this problem ?

thanks

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DM8107 EMAC0 Interface not working in RGMII mode