UART0 in DAMINTERRUPT opmode and baudrate greater than 115200

Hi,

I am working with EVM OMAP L137 and I am trying to transfer a large file through UART0

with dmainterrupt opmode and baudrate set to 921600, but  after a few transfers it get stuck.

With baudrate set to 115200 it works fine.

In the C6748_BIOS user guide,it is mentioned that:

"one needs to tweak the parameter rxThreshold and softTxThreshold  

for higher baudrates".

However, I use the uartSample.c provided in pspdrivers_01_20_00 as reference and 

there is no such field softTxThreshold in the struct Uart_Params. 

So do i just need to add softTxThreshold to the Uart_Params  struct in the Uart.h file, and if so how should i use it?

Could the fields edmaTxTC and edmaRxTC In the Uart_Params ,that set to 0 in the uartSample example, be related?

(couldn't find any explanation to these fields)   

Thanks in advance,

Eyal