From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Authentication-Results: smtp.codeaurora.org; dkim=fail reason="key not found in DNS" (0-bit key) header.d=micronovasrl.com header.i=@micronovasrl.com header.b="JEkPL87O" DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 63C1060767 Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=micronovasrl.com Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752097AbeFFMHy (ORCPT + 25 others); Wed, 6 Jun 2018 08:07:54 -0400 Received: from mail.micronovasrl.com ([212.103.203.10]:60257 "EHLO mail.micronovasrl.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751968AbeFFMHt (ORCPT ); Wed, 6 Jun 2018 08:07:49 -0400 Authentication-Results: mail.micronovasrl.com (amavisd-new); dkim=pass reason="pass (just generated, assumed good)" header.d=micronovasrl.com Subject: Re: [PATCH 4/4] serial: core: Mask mctrl with TIOCM_RTS too if rs485 on and RTS_AFTER_SEND set. To: Andy Shevchenko Cc: matwey.kornilov@gmail.com, Greg Kroah-Hartman , Jiri Slaby , Matthias Brugger , Kees Cook , Sean Young , "open list:SERIAL DRIVERS" , open list References: <20180606094942.71190-1-giulio.benetti@micronovasrl.com> <20180606094942.71190-3-giulio.benetti@micronovasrl.com> From: Giulio Benetti Message-ID: <5bda9e82-369a-ff5f-fef8-f3933c6f1c64@micronovasrl.com> Date: Wed, 6 Jun 2018 14:07:45 +0200 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: it Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Il 06/06/2018 14:03, Andy Shevchenko ha scritto: > On Wed, 2018-06-06 at 11:49 +0200, Giulio Benetti wrote: >> If rs485 is enabled and RTS_AFTER_SEND is set on startup need to keep >> TIOCM_RTS asserted to keep rs485 transceiver in RX when idle. >> >> Check if rs485 is on and RTS_AFTER_SEND is set and mask port->mctrl >> with >> TIOCM_RTS too and not only TIOCM_DTR. >> > > This one feels wrong to be in serial_core.c. Perhaps in 8250/8250*.c. I've tried to avoid modifying serial_core.c but if it masks mctrl only with TIOCM_DTR, it forces RTS unasserted. Another way could be: If rs485 ON and RTS_AFTER_SEND set, then ignore RTS driving in 8250_set_mctrl, would it make sense? Thanks -- Giulio Benetti CTO MICRONOVA SRL Sede: Via A. Niedda 3 - 35010 Vigonza (PD) Tel. 049/8931563 - Fax 049/8931346 Cod.Fiscale - P.IVA 02663420285 Capitale Sociale € 26.000 i.v. Iscritta al Reg. Imprese di Padova N. 02663420285 Numero R.E.A. 258642