This patchset addresses the issue of unwanted local echo during half-duplex RS485 transmissions within the OMAP serial driver. The first patch disables all RX-related interrupts in the serial_omap_stop_rx(), which is called from serial_omap_start_tx() before the start of a half-duplex transmission. It also makes sure that whatever is disabled by serial_omap_stop_rx(), is subsequently re-enabled in serial_omap_stop_tx() when the half-duplex transmission is complete. The second patch empties the RX FIFO of the OMAP UART at the end of a half-duplex TX. This is required when using a transceiver such as the Intersil ISL3332, which does not provide a way to disable the receiver during a half-duplex transmission. Both patches have been successfully tested on a Beaglebone Black with ttyO2 and ttyO4 wired to an Intersil ISL3332 dual port transceiver, while communicating with 3-wire RS485 half-duplex (MODBUS) devices. Dimitris Lampridis (2): tty/serial: omap: fix RX interrupt enable/disable in half-duplex TX tty/serial: omap: empty the RX FIFO at the end of half-duplex TX drivers/tty/serial/omap-serial.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) -- 1.7.10.4 -- 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
