We are using the imx6ULL processor MCIMX6Y2CVM05AA and RS485 transceiver IC ST485BDR in our design.We are facing a similar issue related to RS485 RTS signal as above.We are using the UART port 2 of the processor ( UART2_TX transmit function,UART2_RX for receive function,UART3_RXD pin for TX enable and RX enable of RS485 transceiver).We are using kernel version 4.1.x.x.
We were able to toggle the RTS line of UART2 by configuring it as a GPIO line but we are missing few bytes and not able to receive the complete data.
The transit enable from ULL processor is not going low immediately after the transmission is completed( Highlighted in green in attachment). We are losing few bytes as the delay between the Rx enable and Rx data is very small (Highlighted in Red in attachment).
How can we make the transmit enable signal go low immediately after the transmission is completed ???