Hi Richard,
Your newer kernel uses the name "ttyO0" because it has an OMAP-specific module for the UART (hence the "O").  I get the same "UART: undefined" result from setserial, but my UART works as expected.  You should not try to set the UART type.
Unless I'm missing something, I think everything looks OK.  Do you have a problem sending/receiving data with the UART?

From: Ratmansky, Richard [mailto:richard.ratmansky@lmco.com]
Sent: May 18, 2012 14:18
To: gumstix-users@lists.sourceforge.net
Subject: [Gumstix-users] Overo UART issues



I have two gumstixs, one which is working properly running an older kernel, one that is not working properly built from a newer kernel.  Both kernels were built from the main branch of the gumstix source tree.  I am booting both from sd cards, and swapping sd cards in the gumstix results in the a swap of problematic gumstix. 


The issue belongs to the UARTS on my gumstix.  I installed setserial to help figure out the problem and have the following output:


Good gumstix:


/dev/ttyS0, UART:  16654, Port: 0x0000, IRQ:72


Bad Gumstix:

/dev/ttyO0, UART: undefined, Port: 0x0000, IRQ: 72



You’ll probably notice the device names are not the same.  This is one of the weird things I found when I updated.  I don’t know how to change the ttyO0 to ttyS0, not that I think that is the problem.  Trying to specify the UART type on the bad gumstix results in :


$setserial /dev/ttyO0 uart 16654

Cannot set serial info: Invalid argument


While that exact same command (on the other gumstix using ttyS0) works without error.


I’m at a loss as to what else to try.  I think it must have something to do with improper kernel modules (user space doesn’t show any difference with lsmod).


Any thoughts?