cc6 dma uart - incomplete packets

I’m currently using a cc6 dual-lite to transfer data between an stm32. Running at 115200 baud over uart with dma, I sometimes miss some bytes. For example I have a test that sends 512 bytes of data 4 times a second. Enabling debug of the imx uart driver shows that it doesn’t always get 512 bytes. Sometimes it gets under 512 (eg 500). I would have expected in those cases to see 500 bytes followed by 12 bytes.

Running uart in interrupt mode has no problems but I plan to increase the baud rate up to 1Mbps.


Are you using HW flow control?
Please check
see first answer:
please check attached Linux Manual Chapter 39
Universal Asynchronous Receiver/Transmitter (UART) Driver

If you want to use the DMA support for UART please also
enable the RTS/CTS for it. The DMA may be abnormal if you
do not enable the RTS/CTS.

Perhaps this is your issue as well?