FEC workign in uboot but not in kernel

[MarkoPanger]

Hello,

I'm using yocto to build a image for our custom board. The board is based on sabreSD board. So far I've managed to port uboot to it, but I'm struggling a bit with the kernel image.

When uboot (U-Boot 2013.04) boots I'm using tftp to get the uImage and my DTB file and later on I'm booting Linux (3.10.17-1.0.0) via a NFS mounted rootfs. So far so good.

In the process of booting Linux, juts before the kernel tries to mount NFS it stuck in getting an IP address from our DHCP server. I've verified that we have valid MAC. What is strange is that uboot is capable of getting an IP form DHCP. More, half on the FEC/PHY seems to work as if I disconnect the ETH cable I'm able to see "link is down" on the console and vice-versa if I plug the cable.

Another important fact is that our custom board is identical to the sabre board in regards to the ethernet functionality.

Here is where the console output is stuck retrying:

IP-Config: Retrying forever (NFS root)...

fec 2188000.ethernet eth0: Freescale FEC PHY driver [Generic PHY] (mii_bus:phy_addr=2188000.ethernet:01, irq=-1)

Sending DHCP requests .libphy: 2188000.ethernet:01 - Link is Up - 100/Full

..... timed out!

Any idea why DHCP works using u-boot and not when using the kernel image ?

Marko

[MarkoPanger]

Update: Looks like VGEN1 which powers the RGMII power rail is being shut down in the boot process. This causes my RGMII lines to be at 1V rather that 1.5V.

[MarkoPanger · Accepted solution]

Found it.

I've added "regulator-always-on" token under VGEN1 regulator and that did  the job.

M.

[avinashh]

Hello,

I'm facing the same issue with P2041 QORIQ processor. If this could be the problem to mange also,  how do I fix this. Request you to support please.

Thanks and regards,

Avinash H