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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5E33CC433F5 for ; Fri, 8 Apr 2022 12:27:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235697AbiDHM3i (ORCPT ); Fri, 8 Apr 2022 08:29:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53296 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230149AbiDHM33 (ORCPT ); Fri, 8 Apr 2022 08:29:29 -0400 Received: from mx07-00178001.pphosted.com (mx07-00178001.pphosted.com [185.132.182.106]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 510EA33DCAB; Fri, 8 Apr 2022 05:27:25 -0700 (PDT) Received: from pps.filterd (m0288072.ppops.net [127.0.0.1]) by mx07-00178001.pphosted.com (8.16.1.2/8.16.1.2) with ESMTP id 2389j3P9000551; Fri, 8 Apr 2022 14:27:05 +0200 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 : content-transfer-encoding; s=selector1; bh=OzzsSeRZXTJPRZje9ui1T8+kROrim9zZTezfZrmqwVA=; b=g9pEZNsoYYlGs5g2LsrK5fLiu589Fxw1KHMSO0CId/eEqsrdIBXj6aKTW+eD8ltMsGgE Lmo260J0JhOSP7+0q6M1B/R9dJ8DCktbMGqZ4jU2MR7bKblxcZXYXDj/HLenA4x6JuV1 GxpxUrt+JnIKxaEH85wK6gRR3zIVInqb0/T9CmSzK552YxFgLzHvfOtY4DTLLw1xbbZ5 UDIaiJV5O85hvXJlE1uKarAfUTL6j0LghhtsifE0PWAyBmwTkxVuycc8aH7RWkhJKjM4 kfPbnN04JyVNJ+xhM1hlbpHavSUKqxYxE4CW7HuDrOs7s5HvpWs8CQinBrJROwov5khc 7Q== Received: from beta.dmz-eu.st.com (beta.dmz-eu.st.com [164.129.1.35]) by mx07-00178001.pphosted.com (PPS) with ESMTPS id 3f9wr7r1p9-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 08 Apr 2022 14:27:05 +0200 Received: from euls16034.sgp.st.com (euls16034.sgp.st.com [10.75.44.20]) by beta.dmz-eu.st.com (STMicroelectronics) with ESMTP id 8EA7B100038; Fri, 8 Apr 2022 14:27:03 +0200 (CEST) Received: from Webmail-eu.st.com (sfhdag2node2.st.com [10.75.127.5]) by euls16034.sgp.st.com (STMicroelectronics) with ESMTP id 8666321A21E; Fri, 8 Apr 2022 14:27:03 +0200 (CEST) Received: from localhost (10.75.127.50) by SFHDAG2NODE2.st.com (10.75.127.5) with Microsoft SMTP Server (TLS) id 15.0.1497.26; Fri, 8 Apr 2022 14:27:03 +0200 From: Valentin Caron To: Greg Kroah-Hartman , Jonathan Corbet CC: Jiri Slaby , Maxime Coquelin , Alexandre Torgue , Erwan Le Ray , Valentin Caron , , , , , Subject: [PATCH V2 1/3] serial: stm32: remove infinite loop possibility in putchar function Date: Fri, 8 Apr 2022 14:26:34 +0200 Message-ID: <20220408122636.505737-2-valentin.caron@foss.st.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220408122636.505737-1-valentin.caron@foss.st.com> References: <20220408122636.505737-1-valentin.caron@foss.st.com> MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-Originating-IP: [10.75.127.50] X-ClientProxiedBy: SFHDAG2NODE1.st.com (10.75.127.4) To SFHDAG2NODE2.st.com (10.75.127.5) X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.858,Hydra:6.0.425,FMLib:17.11.64.514 definitions=2022-04-08_04,2022-04-08_01,2022-02-23_01 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Rework stm32_usart_console_putchar() function in order to anticipate the case where the character can never be sent. Signed-off-by: Valentin Caron --- drivers/tty/serial/stm32-usart.c | 12 +++++++++--- drivers/tty/serial/stm32-usart.h | 2 ++ 2 files changed, 11 insertions(+), 3 deletions(-) diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c index 87b5cd4c9743..83895da84891 100644 --- a/drivers/tty/serial/stm32-usart.c +++ b/drivers/tty/serial/stm32-usart.c @@ -1645,10 +1645,16 @@ static void stm32_usart_console_putchar(struct uart_port *port, unsigned char ch { struct stm32_port *stm32_port = to_stm32_port(port); const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; + u32 isr; + int ret; - while (!(readl_relaxed(port->membase + ofs->isr) & USART_SR_TXE)) - cpu_relax(); - + ret = readl_relaxed_poll_timeout_atomic(port->membase + ofs->isr, isr, + (isr & USART_SR_TXE), 100, + STM32_USART_TIMEOUT_USEC); + if (ret != 0) { + dev_err(port->dev, "Error while sending data in UART TX : %d\n", ret); + return; + } writel_relaxed(ch, port->membase + ofs->tdr); } diff --git a/drivers/tty/serial/stm32-usart.h b/drivers/tty/serial/stm32-usart.h index feab952aec16..d734c4a5fd24 100644 --- a/drivers/tty/serial/stm32-usart.h +++ b/drivers/tty/serial/stm32-usart.h @@ -251,6 +251,8 @@ struct stm32_usart_info stm32h7_info = { #define RX_BUF_P (RX_BUF_L / 2) /* dma rx buffer period */ #define TX_BUF_L RX_BUF_L /* dma tx buffer length */ +#define STM32_USART_TIMEOUT_USEC USEC_PER_SEC /* 1s timeout in µs */ + struct stm32_port { struct uart_port port; struct clk *clk; -- 2.25.1