i am using a kernel 3.10.17 on a board very similar to sabre-lite board.
I have an HCI/ BT module connected on uart2, that needs flow control.
After reset, the module sends on UART TX (imx6 RX) a train of data, scanning for firmware to be downloaded from bluez hciattach.
With pinmux settings for CTS and RTS commented out, i see the burst of data only on imx6 RX, as it should be, and i can upload the firmware successfully. Just after i have issues since the flow control is off.
If i enable pinmux ctrl pins for CTS and RTS, i see this burst of data in TX replicated on RX pin, RTS and CTS pins. And due to same train of data also in imx6 TX, i cannot upload the firmware anymore. Why this signal is now on all 4 UART pins ?