I made a custom Tobi-Duo (the only change to the Tobi-Duo schematic was the addition of the FTDI usb-serial) to do some in-line network functions, but I am having trouble getting the lan9221 chips to work. I triple checked and had a friend independently verify that that I copied the Tobi-Duo schematic perfectly, but U-boot says "No ethernet found". I have several Overo Waters, all of which work on the Tobi-Duo, and on regular Tobi's.
It looks to me like there is a hardware problem, but I have no idea how to diagnose it. I cannot use ethtool to send messages to either interface because the kernel doesn't load any ethernet functionality because it can't communicate with the lan9221's when it boots up. I could very easily diagnose the problem if I had a way to send messages out the MII. I searched pretty deep in the archives and I couldn't find answers, so hopefully someone can answer these newbie questions, or point me to where they have been answered previously:
Is there some configuration that has to be done on the lan9221's to get them to work together on one Overo, or even by themselves?
How do I force an ethernet interface to be installed after Uboot decides there isn't ethernet?
The datasheet gives no information on the smsc lan9221 VDD18CORE pin other than a name, but on my board that pin produces 2.4V, while on the Tobi and Tobi duo it produces 1.8V. Is this a configuration issue?
On Fri, Apr 27, 2012 at 2:59 PM, Nick Wernicke <[hidden email]> wrote:
> Is there some configuration that has to be done on the lan9221's to get them
> to work together on one Overo, or even by themselves?
> How do I force an ethernet interface to be installed after Uboot decides
> there isn't ethernet?
> The datasheet gives no information on the smsc lan9221 VDD18CORE pin other
> than a name, but on my board that pin produces 2.4V, while on the Tobi and
> Tobi duo it produces 1.8V. Is this a configuration issue?
There is not much in the way of configuration for the second ethernet
chip (have a look at the board/overo/overo.c in the uboot source code
and search for TOBI_DUO ) and if this code works on a normal tobi-duo,
it should work on your device.
I'd be pretty suspicious of the 2.4V and would check the following:
1. Are the other voltage rails on the board correct?
2. Are there any shorts on the board (in the PCB or between components)?
3. Do you have the correct chip soldered on the board? (I know, this
seems like a crazy thing to check but I've heard of bad chips getting