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=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 E2A1EC33C9A for ; Mon, 6 Jan 2020 01:18:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B473A2072C for ; Mon, 6 Jan 2020 01:18:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="kUkML9Or" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727357AbgAFBR1 (ORCPT ); Sun, 5 Jan 2020 20:17:27 -0500 Received: from mail-lf1-f68.google.com ([209.85.167.68]:36254 "EHLO mail-lf1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727170AbgAFBR0 (ORCPT ); Sun, 5 Jan 2020 20:17:26 -0500 Received: by mail-lf1-f68.google.com with SMTP id n12so35324335lfe.3; Sun, 05 Jan 2020 17:17:24 -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=kUkML9OrabwAEvWeZsnyBC7uNshLNoKhsWdF/XhXTjEArYIMFGZy1/9+c9uyWp6veo Cu01hB5n9NRIkEoX8pzRCbOx4amSb4gQ2WwVCuhvj5pctPwbVEL6IZyHpZJ0HlsNVEz6 sFH5O+iJM9fsJ1GXfTW8iErxK+I3NfsV+LgOrxU0NM1bL8O7BT2yICh+6jtGtXNrjAHs Q7CTKT5IPh1kRixqQWeMjcFnPZc0d6KH7UAGihWw73vFa7iHx5EZzmVr6S0a06fo060j YdcvsaGfIPX5BsOqnC6cSNNKJvZCgw+6m6ehr5JL/qYvwlVZZbEv7rab6bAJZk6LYY7z L3Lw== 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=FsLXhpjnCMcZTwbqVy4pDg8rppO3hMmLoK6/cO+Q6OdJ+wR4ixVyvHNoZsiI1DbkXR 3jJGs0aLhKAGTXie94MlBbyAAhgX6SC5t9ccCmc/VKaUsi3WSYcxGx1eSEy5Y57f2pHY l7+Ex+TAL6cvjtlwwB4HOWu+opGRCQBlFoVduKPfuhnk6i92hp/AR5G3MEk43PDS9+nS WwzpbSDDEFI6i0w5umhjmPvJMOXXkEfdDU6KlssXVq9hn4vZSvZd5HPhtcTOYVOuzhM4 sma4Lf+IduxmZ+1AGrXeUq/U81eO118MvBCbn3yZHnQyaeM9vHul8XlY8+LCwTZGNQTJ 2dYQ== X-Gm-Message-State: APjAAAXojcvmbxd+CM1A6O8Nkf/0itvCbn2xkxbNk4x0rTzNWpJ1fQNp I4/FSPdGSGPAXt3Pm5u/Xbk= X-Google-Smtp-Source: APXvYqwwCWxjRa08Q9QsCh5DWxn6v0JUV2txxv78VLf9uv7Zi78RSe26MCLNWRtfzT8ZyBqXcEgfJw== X-Received: by 2002:ac2:43a7:: with SMTP id t7mr51491468lfl.125.1578273444243; Sun, 05 Jan 2020 17:17:24 -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 y14sm28353271ljk.46.2020.01.05.17.17.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 05 Jan 2020 17:17:23 -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 v3 03/13] dmaengine: tegra-apb: Prevent race conditions on channel's freeing Date: Mon, 6 Jan 2020 04:16:58 +0300 Message-Id: <20200106011708.7463-4-digetx@gmail.com> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20200106011708.7463-1-digetx@gmail.com> References: <20200106011708.7463-1-digetx@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@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