From patchwork Tue Apr 19 08:53:28 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Valentin Caron X-Patchwork-Id: 12817632 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id F1100C433EF for ; Tue, 19 Apr 2022 08:55:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:CC:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=HJtZV8h/o/VyEdznXGIQ8RPyUFi0H/+LIAr7JmMnJE8=; b=nNfay7+6YdnsxF Hckwsak/KQuD7UvCWGjV/spDrmNON3emC6LR+vNsBSnnUpI5uHkH47l95jDgDfVHQeXnAqp88ouJF 91cR0R5wGiyuBYudBPNEZ+3f0ejNoPX61EyvjXNzh/ZcRAmAQvDwLmStq5MTM20X9TVOry3sUIYQw diGZYzavrrZni2sKZyigmn7CAZN246nkKgn5KB2s6hzvBtwegEk6IBJGff3YQJsGhf1CXzlePEfhq nlEtt/D6l+A65HaBGMr5wsnmOc3zeaBfj25UGH2ix6VtwXmpuh+aJ9idoPx7B0jSBbGs4GpySi4ll Nmcr5miHpzy9bB9GbwLw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1ngjcu-002QSV-A0; Tue, 19 Apr 2022 08:54:24 +0000 Received: from mx08-00178001.pphosted.com ([91.207.212.93] helo=mx07-00178001.pphosted.com) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1ngjce-002QLL-PQ for linux-arm-kernel@lists.infradead.org; Tue, 19 Apr 2022 08:54:10 +0000 Received: from pps.filterd (m0046660.ppops.net [127.0.0.1]) by mx07-00178001.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 23J7mPMJ031599; Tue, 19 Apr 2022 10:53:50 +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=2TdqCQA3HZJgjbQgS4ng8USah1H+t/xStkf042B0x94=; b=kZcqNamzq6IR++gU1x2mp3vOcRGEv6Dz1jLwtnFhO6IauwBm3SwU/PZo2wIbvHSrbo8V DSmquKRilSLdtoieiXx0hrVSdh/GkhuyO//S/v1tsamcY2H4K0vBL4V/XE7vQDVDqIuy FUaHe3aIzuaBBEXoJmwg2VgHOoZtMoPBWB1yg4Ti8ZWeuD+YvpHJjfSK7TE90UxmfNkP FGHJwEMb6ALx3trwuGvI26fFMh04SAYa7QTdH6vxWadySrpmuRBrDOlgR65t3L5vSmo0 CSfbLv3pXZiDocm91oxyp6hCTYrtwpm5+euj+tcohti6Lj++28RDxOxq/ZXqlY9eaVNh Sw== 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 3fh09refje-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 19 Apr 2022 10:53:50 +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 43AD8100034; Tue, 19 Apr 2022 10:53:47 +0200 (CEST) Received: from Webmail-eu.st.com (sfhdag2node2.st.com [10.75.127.5]) by euls16034.sgp.st.com (STMicroelectronics) with ESMTP id 3C1992053D5; Tue, 19 Apr 2022 10:53:47 +0200 (CEST) Received: from localhost (10.75.127.48) by SFHDAG2NODE2.st.com (10.75.127.5) with Microsoft SMTP Server (TLS) id 15.0.1497.26; Tue, 19 Apr 2022 10:53:46 +0200 From: Valentin Caron To: Greg Kroah-Hartman CC: Geert Uytterhoeven , Jiri Slaby , Maxime Coquelin , Alexandre Torgue , Valentin Caron , , , , Subject: [PATCH V3 1/3] serial: stm32: remove infinite loop possibility in putchar function Date: Tue, 19 Apr 2022 10:53:28 +0200 Message-ID: <20220419085330.1178925-2-valentin.caron@foss.st.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220419085330.1178925-1-valentin.caron@foss.st.com> References: <20220419085330.1178925-1-valentin.caron@foss.st.com> MIME-Version: 1.0 X-Originating-IP: [10.75.127.48] 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:6.0.486,FMLib:17.11.64.514 definitions=2022-04-19_03,2022-04-15_01,2022-02-23_01 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220419_015409_438648_5FF7B16C X-CRM114-Status: GOOD ( 18.28 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.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 f886976daef6..9910a18779af 100644 --- a/drivers/tty/serial/stm32-usart.c +++ b/drivers/tty/serial/stm32-usart.c @@ -1640,10 +1640,16 @@ 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;