From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dimitris Lampridis Subject: [PATCH 0/2] tty/serial: omap: remove unwanted local echo during half-duplex TX Date: Thu, 13 Mar 2014 15:11:45 +0200 Message-ID: <1394716307-11248-1-git-send-email-dlampridis@logikonlabs.com> Return-path: Received: from promitheas2.multiserver.gr ([144.76.157.92]:55136 "EHLO promitheas2.multiserver.gr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751154AbaCMNfu (ORCPT ); Thu, 13 Mar 2014 09:35:50 -0400 Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: Greg Kroah-Hartman Cc: Jiri Slaby , linux-serial@vger.kernel.org, Dimitris Lampridis 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