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 9B1F4C33CB3 for ; Thu, 30 Jan 2020 04:42:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 714122082E for ; Thu, 30 Jan 2020 04:42:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="tAXPvMTC" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727520AbgA3EmL (ORCPT ); Wed, 29 Jan 2020 23:42:11 -0500 Received: from mail-wm1-f65.google.com ([209.85.128.65]:37335 "EHLO mail-wm1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726774AbgA3ElS (ORCPT ); Wed, 29 Jan 2020 23:41:18 -0500 Received: by mail-wm1-f65.google.com with SMTP id f129so2583760wmf.2; Wed, 29 Jan 2020 20:41:16 -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=ZP2sBFBGkO5bsS7Y1zFf5pSNHFa7vlci0txeV2iOQs8=; b=tAXPvMTCrcqvRg6DMs4qAACn1NEWJid5v0kQH5SF5VgGTN/xj3GGOaQ8kvUKHayg2v De9yU6DvJ3iePTh39yziabf0/fHH+s9zKgE+wP6txQ5xH10buVKbLVcRLieCM408An83 4BdlXbJFzZpNpevaGS1y3bWO2eaiRbp+0WPp1iTxXEtM9+XrVoeyVYpwExb+MImP5XSQ 8qLBfn5CslXP7bMLUeoayjukOdgtgGvVKBETYa3AU7yACh8CdPuvcd1cZ7D8wZ5CkD4t glH2eXYayRge+OuW6culmBAJS+opwF70p1WA+6rwcg6OE5vFTGH8dB+rsDZf79lJ4a2q QNHw== 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=ZP2sBFBGkO5bsS7Y1zFf5pSNHFa7vlci0txeV2iOQs8=; b=cBmLCQVQtaqlJUHqRbMgmmd6Zge9JSRYUNOjFUxCd4aqXZ6Sj0bnLxVvkNABoDTmsH IwRXpkBjwnBqG9NvA5ajab+shppaBR3jXLhItolpi6v8FZDY7GGpKeGDOmdkiC8gIYop Knd/xr/mASzsxviSDpLIWyMyUK+7XftTWMCGpxBpv1EvVIPXoRozmVJukUlHPyRj2gvR CJYQSvJS5jxsLt98ahWec7tu4Q4doCPHIHnk683iWS/sRUM5xWCSHN+pN0PPORcP40u7 HDewPrh8CVI+an9XO+5vX22nF93wIfFSbvF2GUz3N0l7yuRLc3ZMiARwpjZLamXs0AkO v2Dw== X-Gm-Message-State: APjAAAXJGkOjLbXUjRHbqwOoGRHBxnEtTuvyZgVYSPpAPXkB2jD8tlg/ L9uCpObjcna/3BGKP6liiLeikbJ/ X-Google-Smtp-Source: APXvYqxjG7C8ZCuesf3lZQJXPgxsRAJzh4HtA8uJJsu8/cX1SnVRf98iVX9ukNflN1geDJrkRKTGxQ== X-Received: by 2002:a1c:a381:: with SMTP id m123mr2876157wme.158.1580359275874; Wed, 29 Jan 2020 20:41:15 -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 g128sm4494672wme.47.2020.01.29.20.41.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 29 Jan 2020 20:41:15 -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 v6 04/16] dmaengine: tegra-apb: Prevent race conditions on channel's freeing Date: Thu, 30 Jan 2020 07:37:52 +0300 Message-Id: <20200130043804.32243-5-digetx@gmail.com> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20200130043804.32243-1-digetx@gmail.com> References: <20200130043804.32243-1-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. Acked-by: Jon Hunter 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 f56881500a23..766c2c9eac8e 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