[U-Boot-Users] U-boot serial driver looses characters on at91rm9200-ek board.

Leonid Leonid at a-k-a.net
Fri Jun 22 20:10:48 CEST 2007


Hi:

I'm working with ATMEL at91rm9200-ek reference board and I have recently
noticed that if characters on serial console are typed quickly, U-boot
serial port's driver looses them. It's easy to see if try copy and past
some string > ~20 characters long. I took the string:

"command line: root=/dev/nfs rw nfsroot=192.168.0.137:/tftpboot/leonid/"

After copy/past it looks as following:

"command line:root=/dev/nf rw nfsroot=92.168.0.13:/tftpboot/lonid/"

- many characters are missing.

I realize that it can be terminal related issue as DULG manual points
out so I have performed some investigations:

A. Speed is 115200
 - It happens with minicom and teraterm on U-boot.
 - It doesn't happen while Linux is already running - so, Linux serial
driver is quite reliable (I'm running 2.6.16 now).

B. Speed is 57600 or less
   The issue disappears (or at least doesn't show up with the same
string).

So, we must conclude it must be specific U-boot serial driver problem,
showing up on high speeds.

Does anybody know about any problems with U-boot serial driver for this
ATMEL chip?

Thanks,

Leonid.




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