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=-9.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 68961C33CA7 for ; Sun, 12 Jan 2020 17:31:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3EA85214D8 for ; Sun, 12 Jan 2020 17:31:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="SJjsUnua" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733201AbgALRbm (ORCPT ); Sun, 12 Jan 2020 12:31:42 -0500 Received: from mail-lf1-f67.google.com ([209.85.167.67]:33734 "EHLO mail-lf1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728512AbgALRbe (ORCPT ); Sun, 12 Jan 2020 12:31:34 -0500 Received: by mail-lf1-f67.google.com with SMTP id n25so5171820lfl.0; Sun, 12 Jan 2020 09:31:32 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=cVivrbUaLAvYOWEQyaxZv2B+LG1a8MlZfEIn/W+0au8=; b=SJjsUnuacjwEmmFeP1a4th9a3eAh0uaYtlNT7/X4jvCpH1AI7dHTBFWk0SVlk+b0IH E3hD/TbeBVZHBOEXVL5vr8LQthhIu2TW65i8uVVBOSt6h3cVUp/NmB97oYtccCmB8xx1 gMCqnBds58LoBwEE3Wnze9BFP25Mxj9IVeSVm+I9WVmp07YH/FFuSvbrsfiWlmcdo/80 Q6PgSqmBQeinfTpsuHqALeldYcuX2ZhlTFnl0t4hAqGaT8iYhoBIrHz0iF9jRewRWGUs gnvmjrGTKpb6f8DwiO6i6nQ5re1kqeRMs4jHLbvTxPsvoTdU0QiCvOy/m8HrEiCkE3fE 4sZw== 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:in-reply-to :references:mime-version:content-transfer-encoding; bh=cVivrbUaLAvYOWEQyaxZv2B+LG1a8MlZfEIn/W+0au8=; b=nAelAacijgjj34quagI8X6oD1Av8MAS6cZFRvUz/Bhd2cfeQRLMWmy3dUm/d2O0rsc BSYHkvdAjB3ScQaZ4V7tJ6cnzfegpolcP2aCMnNWFk7fzIEqnoT24CYcnYChHs6yTdOr eFXbCcnc4SySr0QQNF9lILG1PYJSvTiw1vpDXoEeNHqdkc6Dd4z7Pclp55Yr8eW3+es0 xJE8vpwpH3IjiB+A1AwheSEUGI2hihkvQoFd5qICa3Nt+jIPpziEaqP5+NngbAuK0DeG m8l9tNaoFTY9CiLxl/3sYSan2taiKzbgOoVPm+3M+Ia9yA7hWQ4awX4ZTQIs0265NdKp 4/zg== X-Gm-Message-State: APjAAAXjeJsnO1tDEGQRN01el0dRB+dWz6ivRLvQpTFmfP0hUDA0AOpJ xiTCzydUbc5Tz+WIEUi+gHM= X-Google-Smtp-Source: APXvYqxche74SfZP3bBOfOX10phuAZEUaoTHurS8Kbd28t9dK269h60bqAU/0dfFh9UYQFWgHAv9+w== X-Received: by 2002:a19:8a06:: with SMTP id m6mr7003628lfd.99.1578850291621; Sun, 12 Jan 2020 09:31:31 -0800 (PST) Received: from localhost.localdomain (79-139-233-37.dynamic.spd-mgts.ru. [79.139.233.37]) by smtp.gmail.com with ESMTPSA id 140sm4458888lfk.78.2020.01.12.09.31.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 12 Jan 2020 09:31:31 -0800 (PST) From: Dmitry Osipenko To: Laxman Dewangan , Vinod Koul , Dan Williams , Thierry Reding , Jonathan Hunter , =?UTF-8?q?Micha=C5=82=20Miros=C5=82aw?= Cc: dmaengine@vger.kernel.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v4 03/14] dmaengine: tegra-apb: Prevent race conditions on channel's freeing Date: Sun, 12 Jan 2020 20:29:55 +0300 Message-Id: <20200112173006.29863-4-digetx@gmail.com> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20200112173006.29863-1-digetx@gmail.com> References: <20200112173006.29863-1-digetx@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org It's incorrect to check the channel's "busy" state without taking a lock. That shouldn't cause any real troubles, nevertheless it's always better not to have any race conditions in the code. Signed-off-by: Dmitry Osipenko --- drivers/dma/tegra20-apb-dma.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c index 664e9c5df3ba..24ad3a5a04e3 100644 --- a/drivers/dma/tegra20-apb-dma.c +++ b/drivers/dma/tegra20-apb-dma.c @@ -1294,8 +1294,7 @@ static void tegra_dma_free_chan_resources(struct dma_chan *dc) dev_dbg(tdc2dev(tdc), "Freeing channel %d\n", tdc->id); - if (tdc->busy) - tegra_dma_terminate_all(dc); + tegra_dma_terminate_all(dc); spin_lock_irqsave(&tdc->lock, flags); list_splice_init(&tdc->pending_sg_req, &sg_req_list); -- 2.24.0