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=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 E44C7C433B4 for ; Mon, 12 Apr 2021 09:47:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BF52261241 for ; Mon, 12 Apr 2021 09:47:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237892AbhDLJrS (ORCPT ); Mon, 12 Apr 2021 05:47:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45486 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240537AbhDLJeO (ORCPT ); Mon, 12 Apr 2021 05:34:14 -0400 Received: from mail-pg1-x52c.google.com (mail-pg1-x52c.google.com [IPv6:2607:f8b0:4864:20::52c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BEAC1C06136E; Mon, 12 Apr 2021 02:31:44 -0700 (PDT) Received: by mail-pg1-x52c.google.com with SMTP id h25so8919962pgm.3; Mon, 12 Apr 2021 02:31:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=hnbI4HTxy5h+9wDfXPCcQHa6zzBSTTZbMcq2PaN8c1I=; b=HtwrWWFDbFwS9xUN3hU5q5cxt7V3HjRLojvzWMaJ/+Q7zxE0hWxz4n1PDmChYQ/EMq Ak3U1MP/lV0CYn9AmEqHZz+ifgkH6I6+/QmhECchXang6IFWQAEHW9A6hD7hagYiMEz4 H/kK3/agJLcFRlFvNxuYtb9f/xIjVG1zuPoLQ4rMOmw4QWNCSu6I3BWtAO9Dlj8WKL6i Co3WFHvM9aygZHnLFYSrk0+EqAdDReQa210+u9fTjB4qfHYT1hB6rb5M7LqBjuj7O1oH ZYfP6CC3uCwx2zqZFM5zEWg3FfKqKfRehj1eQNcK8hf4ymWvRwSMr9xzt6ulIU9gqIuD seSQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=hnbI4HTxy5h+9wDfXPCcQHa6zzBSTTZbMcq2PaN8c1I=; b=HFyEMf116ARbD/I66f7ex4ah76o6YHjwkhCVMWEAntIzFTf78Nq/M65/eRqNXfeKKP pgRvgyrs8JHAl9vfEFnibZXts3tilB3j1r+XelXJR1lJ+A/ff/4PtE9Rx6r6Wb+1u3ru Jp2+AodNKvqfZvmGi2p9Ta+pXlFmmz5ND9ZC9Y5rIvx3+SsYTOL2IOTaOJAcf4ATKO8R OT3NL5pSPufRH7Op/Me7oLNtGlkSYRhcXBmhUW/ae9rRUSvNfuPFHkbbKHUQHHXvv0on GjH9qQAL18/xzmbq9Gtg1sDefG0pSCJavIQaOaK2faOiStmBpw0xgo61vdrlTKM59dU/ pmsw== X-Gm-Message-State: AOAM533crW5lZP5ZOAClVzLj+m+jROE1T2LI4Zw6yZUEVQl4kQsQnHCz cOCK+eh3l9f5hSWvbCPyNGc= X-Google-Smtp-Source: ABdhPJwrTzAtgMMxUCRMcseHM+9n719hVrbqnEqDcTiqRlECpevvVYQUFcWEy8URy2tQJXlZxa0hxg== X-Received: by 2002:a65:68d9:: with SMTP id k25mr9891189pgt.236.1618219904290; Mon, 12 Apr 2021 02:31:44 -0700 (PDT) Received: from fmin-OptiPlex-7060.nreal.work ([137.59.103.165]) by smtp.gmail.com with ESMTPSA id r6sm10511879pgp.64.2021.04.12.02.31.40 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Mon, 12 Apr 2021 02:31:43 -0700 (PDT) From: dillon.minfei@gmail.com To: gregkh@linuxfoundation.org, jirislaby@kernel.org, mcoquelin.stm32@gmail.com, alexandre.torgue@foss.st.com, lkp@intel.com Cc: linux-serial@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kbuild-all@lists.01.org, clang-built-linux@googlegroups.com, dillon min , Gerald Baeza , Erwan Le Ray Subject: [PATCH v2] serial: stm32: optimize spin lock usage Date: Mon, 12 Apr 2021 17:31:38 +0800 Message-Id: <1618219898-4600-1-git-send-email-dillon.minfei@gmail.com> X-Mailer: git-send-email 2.7.4 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: dillon min To avoid potential deadlock in spin_lock usage, use spin_lock_irqsave, spin_trylock_irqsave(), spin_unlock_irqrestore() in process context. remove unused local_irq_save/restore call. Cc: Alexandre Torgue Cc: Maxime Coquelin Cc: Gerald Baeza Cc: Erwan Le Ray Reported-by: kernel test robot Signed-off-by: dillon min --- v2: remove unused code from stm32_usart_threaded_interrupt() according from Greg's review. drivers/tty/serial/stm32-usart.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c index b3675cf25a69..b1ba5e36e36e 100644 --- a/drivers/tty/serial/stm32-usart.c +++ b/drivers/tty/serial/stm32-usart.c @@ -1354,13 +1354,12 @@ static void stm32_usart_console_write(struct console *co, const char *s, u32 old_cr1, new_cr1; int locked = 1; - local_irq_save(flags); if (port->sysrq) locked = 0; else if (oops_in_progress) - locked = spin_trylock(&port->lock); + locked = spin_trylock_irqsave(&port->lock, flags); else - spin_lock(&port->lock); + spin_lock_irqsave(&port->lock, flags); /* Save and disable interrupts, enable the transmitter */ old_cr1 = readl_relaxed(port->membase + ofs->cr1); @@ -1374,8 +1373,7 @@ static void stm32_usart_console_write(struct console *co, const char *s, writel_relaxed(old_cr1, port->membase + ofs->cr1); if (locked) - spin_unlock(&port->lock); - local_irq_restore(flags); + spin_unlock_irqrestore(&port->lock, flags); } static int stm32_usart_console_setup(struct console *co, char *options) -- 2.7.4