On Thu, Jan 17, 2019 at 09:21:09AM -0800, Matthias Kaehlcke wrote: > I observed that the qcom_geni_serial driver doesn't raise RTS with > flow control disabled. It seems we have to investigate why that's the > case. I agree that the driver should be platform agnostic. Sounds like a driver bug, unless the hardware is just "odd". The driver implementation of this looks very non-standard judging from a quick peek. In fact, qcom_geni_serial_get_mctrl() is currently a no-op if hardware flow control is not enabled: if (uart_console(uport) || !uart_cts_enabled(uport)) return; Perhaps dropping the !uart_cts_enabled() test is sufficient. Johan