From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AFB4CC43218 for ; Tue, 11 Jun 2019 12:44:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 89DE220896 for ; Tue, 11 Jun 2019 12:44:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388478AbfFKMoS (ORCPT ); Tue, 11 Jun 2019 08:44:18 -0400 Received: from mga14.intel.com ([192.55.52.115]:38430 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727733AbfFKMoS (ORCPT ); Tue, 11 Jun 2019 08:44:18 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga103.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 11 Jun 2019 05:44:18 -0700 X-ExtLoop1: 1 Received: from smile.fi.intel.com (HELO smile) ([10.237.68.145]) by orsmga002.jf.intel.com with ESMTP; 11 Jun 2019 05:44:15 -0700 Received: from andy by smile with local (Exim 4.92) (envelope-from ) id 1hag8N-00059q-0l; Tue, 11 Jun 2019 15:44:15 +0300 Date: Tue, 11 Jun 2019 15:44:15 +0300 From: Andy Shevchenko To: Stefan Roese Cc: linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, Yegor Yefremov , Mika Westerberg , Giulio Benetti , Greg Kroah-Hartman Subject: Re: [PATCH 2/2 v5] tty/serial/8250: use mctrl_gpio helpers Message-ID: <20190611124415.GT9224@smile.fi.intel.com> References: <20190611105603.4435-1-sr@denx.de> <20190611105603.4435-2-sr@denx.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190611105603.4435-2-sr@denx.de> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jun 11, 2019 at 12:56:03PM +0200, Stefan Roese wrote: > From: Yegor Yefremov > > This patch permits the usage for GPIOs to control > the CTS/RTS/DTR/DSR/DCD/RI signals. > static inline void serial8250_out_MCR(struct uart_8250_port *up, int value) > { > serial_out(up, UART_MCR, value); > + > + if (up->gpios) { > + int mctrl_gpio = 0; > + > + if (value & UART_MCR_RTS) > + mctrl_gpio |= TIOCM_RTS; > + if (value & UART_MCR_DTR) > + mctrl_gpio |= TIOCM_DTR; > + > + mctrl_gpio_set(up->gpios, mctrl_gpio); > + } > } > > static inline int serial8250_in_MCR(struct uart_8250_port *up) > { > - return serial_in(up, UART_MCR); > + int mctrl; > + > + mctrl = serial_in(up, UART_MCR); > + > + if (up->gpios) { > + int mctrl_gpio = 0; > + > + /* save current MCR values */ > + if (mctrl & UART_MCR_RTS) > + mctrl_gpio |= TIOCM_RTS; > + if (mctrl & UART_MCR_DTR) > + mctrl_gpio |= TIOCM_DTR; > + > + mctrl_gpio = mctrl_gpio_get_outputs(up->gpios, &mctrl_gpio); > + if (mctrl_gpio & TIOCM_RTS) > + mctrl |= UART_MCR_RTS; > + else > + mctrl &= ~UART_MCR_RTS; > + > + if (mctrl_gpio & TIOCM_DTR) > + mctrl |= UART_MCR_DTR; > + else > + mctrl &= ~UART_MCR_DTR; > + } > + > + return mctrl; > } These are using OR logic with potentially volatile data. Shouldn't we mask unused bits in UART_MCR in case of up->gpios != NULL? > + if (up->gpios == 0) This is type inconsistency with this check as far as I understand. I guess you have to do either (up->gpios == NULL), or (!up->gpios). > ret = 0; + Blank line. > + if (up->gpios) > + return mctrl_gpio_get(up->gpios, &ret); -- With Best Regards, Andy Shevchenko