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[79.139.233.37]) by smtp.gmail.com with ESMTPSA id g15sm11563944ljl.10.2019.12.29.06.56.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 29 Dec 2019 06:56:46 -0800 (PST) From: Dmitry Osipenko To: Laxman Dewangan , Vinod Koul , Dan Williams , Thierry Reding , Jonathan Hunter Cc: dmaengine@vger.kernel.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 03/12] dmaengine: tegra-apb: Prevent race conditions on channel's freeing Date: Sun, 29 Dec 2019 17:55:16 +0300 Message-Id: <20191229145525.533-4-digetx@gmail.com> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191229145525.533-1-digetx@gmail.com> References: <20191229145525.533-1-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 unsafe to check the channel's "busy" state without taking a lock, it is also unsafe to assume that tasklet isn't in-fly. Signed-off-by: Dmitry Osipenko --- drivers/dma/tegra20-apb-dma.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c index 664e9c5df3ba..28aff0b9763e 100644 --- a/drivers/dma/tegra20-apb-dma.c +++ b/drivers/dma/tegra20-apb-dma.c @@ -1294,8 +1294,8 @@ 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); + tasklet_kill(&tdc->tasklet); spin_lock_irqsave(&tdc->lock, flags); list_splice_init(&tdc->pending_sg_req, &sg_req_list); @@ -1543,7 +1543,6 @@ static int tegra_dma_probe(struct platform_device *pdev) struct tegra_dma_channel *tdc = &tdma->channels[i]; free_irq(tdc->irq, tdc); - tasklet_kill(&tdc->tasklet); } pm_runtime_disable(&pdev->dev); @@ -1563,7 +1562,6 @@ static int tegra_dma_remove(struct platform_device *pdev) for (i = 0; i < tdma->chip_data->nr_channels; ++i) { tdc = &tdma->channels[i]; free_irq(tdc->irq, tdc); - tasklet_kill(&tdc->tasklet); } pm_runtime_disable(&pdev->dev); -- 2.24.0