From patchwork Thu Jan 23 23:03:14 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dmitry Osipenko X-Patchwork-Id: 1228604 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-tegra-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20161025 header.b=PqNT+1dz; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 483dM01RJhz9sR8 for ; Fri, 24 Jan 2020 10:11:40 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730100AbgAWXLj (ORCPT ); Thu, 23 Jan 2020 18:11:39 -0500 Received: from mail-wm1-f66.google.com ([209.85.128.66]:53253 "EHLO mail-wm1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729789AbgAWXKt (ORCPT ); Thu, 23 Jan 2020 18:10:49 -0500 Received: by mail-wm1-f66.google.com with SMTP id m24so4370914wmc.3; Thu, 23 Jan 2020 15:10:48 -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=nxiPwqrpg97YIQpnnmiKVkwXa7j5aarnOTijl3cNiEE=; b=PqNT+1dztXD8+0QAtDUL3L2CcSTzrFIonPzJAPJvVHjiP97fqctFWwWlBF5VxzrUBV lMrHegpRFSPPRB0reJ2XSLh3QOBBk824fPucbkM/KzAsKft12Gv6IWCRzVbE64Zkg3ar 8KpkR8OFdvavyqfS7sdbFTWoATY5cVJtsUvYJttN+KLLQMwAQjTbRix8XttkCX3KKefJ G0U5Blwhmr1azKY7LJeWEl4cr9XST641oRDgnHuxvkek1gNTS9gxYjQ+z/uwp8DVwd+G e5LUZhomSW140fla9BAmsWWnTCjF6qCHpzt0m74Z/q4SDCyqIfuRBT4vKcjwVS47beWx yvvg== 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=nxiPwqrpg97YIQpnnmiKVkwXa7j5aarnOTijl3cNiEE=; b=YI+k7tkY4BU4/0upvGcB+3NAM5yLVDWrQo+A9J6DqI0peSaUOMh6ha8oaocmTSB0jF unPfYWAkPkOjI6KvXxcrLLWjhgRCVoGT1YxvBtgTZz86Y1C1iXYpJw0G5lPmXJEbS63m 00Lx30f4PbDgY6jNfY5xH5r8ZaCx31n7EihQbwqnCURYda13JMvhIfjwLgd83p/FwHEk 1bIsnEDjNuRayZatT/mPL75VdagRn+d3p/8JfZyy8+5riyqteMjwH+CKuXce85VEvFow kZs/lgPEyONcVfdG5/B3mZ0XPhgcEKw81ESNgpzJL8ah/gw63nNEn1YL+osN1jI5la1w IFBg== X-Gm-Message-State: APjAAAVKvm5nLesLR4O8kGI8xtLYym91rwsQTh9Lm4Y9J7wXVObDmEas wZZeWpKoFDYUoWnBFYiFWTg= X-Google-Smtp-Source: APXvYqxYe2ONJh2cqACIU9hiNIHGZ12ItUDr/D3dtWsqTbEsjOvl9SVtermYtiNkIz/t/+dIcJM/ug== X-Received: by 2002:a05:600c:2c53:: with SMTP id r19mr248958wmg.39.1579821047357; Thu, 23 Jan 2020 15:10:47 -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 z6sm5105552wrw.36.2020.01.23.15.10.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 23 Jan 2020 15:10:46 -0800 (PST) From: Dmitry Osipenko To: Laxman Dewangan , Vinod Koul , Dan Williams , Thierry Reding , Jonathan Hunter , =?utf-8?b?TWljaGHFgiBNaXJvc8WC?= =?utf-8?q?aw?= Cc: dmaengine@vger.kernel.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v5 03/14] dmaengine: tegra-apb: Prevent race conditions on channel's freeing Date: Fri, 24 Jan 2020 02:03:14 +0300 Message-Id: <20200123230325.3037-4-digetx@gmail.com> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20200123230325.3037-1-digetx@gmail.com> References: <20200123230325.3037-1-digetx@gmail.com> MIME-Version: 1.0 Sender: linux-tegra-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-tegra@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 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);