Hi, Using upstream I noticed that RS-485 does not work in the default configuration for our platforms (Toradex Apalis/Colibri). Closer debugging shows that it is related to "serial: imx: default to half duplex rs485". We use the i.MX UART in DTE mode and control the RS-485 transceiver using the RTS signal in low-active mode. uart-has-rtscts; fsl,dte-mode; linux,rs485-enabled-at-boot-time; rs485-rts-active-low; Using this setting leads to the RTS signal not getting asserted (the oscilloscope only shows a very short fluke before the start bit is sent). However, using uart-has-rtscts; fsl,dte-mode; linux,rs485-enabled-at-boot-time; rs485-rts-active-low; rs485-rx-during-tx; Asserts the RTS signal low active just fine... Is this a known problem? Any idea where that could come from? It looks as if the receiver part is actually enabling RTS...? Also, isn't enabling RX even in half-duplex mode quite common in order to detect collisions? -- Stefan -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
