From patchwork Fri Feb 19 17:47:26 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Erwan LE RAY X-Patchwork-Id: 385172 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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT 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 B2397C433DB for ; Fri, 19 Feb 2021 17:48:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 85C7464E15 for ; Fri, 19 Feb 2021 17:48:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230036AbhBSRsh (ORCPT ); Fri, 19 Feb 2021 12:48:37 -0500 Received: from mx07-00178001.pphosted.com ([185.132.182.106]:23570 "EHLO mx07-00178001.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229515AbhBSRsf (ORCPT ); Fri, 19 Feb 2021 12:48:35 -0500 Received: from pps.filterd (m0046668.ppops.net [127.0.0.1]) by mx07-00178001.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 11JHgSl8008222; Fri, 19 Feb 2021 18:47:43 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=foss.st.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-type; s=selector1; bh=SDtiqzVwKsf+YjFTaNS2i0bX7wxYrmzVYHBSUD03uSo=; b=2ctwL0BNb90eqS8bSxXV4gNi3qGPWTdy9JsItMQ8NCGegr6/fRN376r2tRj4DFVabhrq eAV6N6fXVTR05g38ErahgvUabGGhg2d9ebTI1S5DyjN0HTwm8naxpbHgNTMSwDsZsd7i 89sh5AVgp12+QEvb+kC/h0kwa8yKaoNgaiUZ6/DSUFxbRpQj/Fteiz1Um8wpqCduAAuu 2KmRJdggh9qmO6h2RfMiikuvm47MoOg+f7oO7CE944ozKVX6ZVNjx7a20e2QbIAXbvKp 9uNi/4zvswAOs7Gp9PiqkNfTSO6Y6ZYwikKFtFbIhwAC+ADY7whA7qfR1o1rFTo3qzVg Bw== Received: from beta.dmz-eu.st.com (beta.dmz-eu.st.com [164.129.1.35]) by mx07-00178001.pphosted.com with ESMTP id 36sqadhaws-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 19 Feb 2021 18:47:43 +0100 Received: from euls16034.sgp.st.com (euls16034.sgp.st.com [10.75.44.20]) by beta.dmz-eu.st.com (STMicroelectronics) with ESMTP id 6A275100034; Fri, 19 Feb 2021 18:47:43 +0100 (CET) Received: from Webmail-eu.st.com (sfhdag2node3.st.com [10.75.127.6]) by euls16034.sgp.st.com (STMicroelectronics) with ESMTP id 5EA1425F3FC; Fri, 19 Feb 2021 18:47:43 +0100 (CET) Received: from localhost (10.75.127.44) by SFHDAG2NODE3.st.com (10.75.127.6) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Fri, 19 Feb 2021 18:47:43 +0100 From: Erwan Le Ray To: Greg Kroah-Hartman , Jiri Slaby , Maxime Coquelin , Alexandre Torgue CC: , , , , Erwan Le Ray , Fabrice Gasnier , Valentin Caron Subject: [PATCH 03/13] serial: stm32: fix incorrect characters on console Date: Fri, 19 Feb 2021 18:47:26 +0100 Message-ID: <20210219174736.1022-4-erwan.leray@foss.st.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210219174736.1022-1-erwan.leray@foss.st.com> References: <20210219174736.1022-1-erwan.leray@foss.st.com> MIME-Version: 1.0 X-Originating-IP: [10.75.127.44] X-ClientProxiedBy: SFHDAG1NODE1.st.com (10.75.127.1) To SFHDAG2NODE3.st.com (10.75.127.6) X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.369, 18.0.761 definitions=2021-02-19_08:2021-02-18,2021-02-19 signatures=0 Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org Incorrect characters are observed on console during boot. This issue occurs when init/main.c is modifying termios settings to open /dev/console on the rootfs. This patch adds a waiting loop in set_termios to wait for TX shift register empty (and TX FIFO if any) before stopping serial port. Fixes: 48a6092fb41f ("serial: stm32-usart: Add STM32 USART Driver") Signed-off-by: Erwan Le Ray diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c index 33a479062948..7710de947aa3 100644 --- a/drivers/tty/serial/stm32-usart.c +++ b/drivers/tty/serial/stm32-usart.c @@ -738,8 +738,9 @@ static void stm32_usart_set_termios(struct uart_port *port, unsigned int baud, bits; u32 usartdiv, mantissa, fraction, oversampling; tcflag_t cflag = termios->c_cflag; - u32 cr1, cr2, cr3; + u32 cr1, cr2, cr3, isr; unsigned long flags; + int ret; if (!stm32_port->hw_flow_control) cflag &= ~CRTSCTS; @@ -748,6 +749,15 @@ static void stm32_usart_set_termios(struct uart_port *port, spin_lock_irqsave(&port->lock, flags); + ret = readl_relaxed_poll_timeout_atomic(port->membase + ofs->isr, + isr, + (isr & USART_SR_TC), + 10, 100000); + + /* Send the TC error message only when ISR_TC is not set. */ + if (ret) + dev_err(port->dev, "Transmission is not complete\n"); + /* Stop serial port and reset value */ writel_relaxed(0, port->membase + ofs->cr1);