Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753379AbbHRNwb (ORCPT ); Tue, 18 Aug 2015 09:52:31 -0400 Received: from hqemgate15.nvidia.com ([216.228.121.64]:16772 "EHLO hqemgate15.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752691AbbHRNuR (ORCPT ); Tue, 18 Aug 2015 09:50:17 -0400 X-PGP-Universal: processed; by hqnvupgp08.nvidia.com on Tue, 18 Aug 2015 06:50:16 -0700 From: Jon Hunter To: Laxman Dewangan , Vinod Koul , Stephen Warren , Thierry Reding , Alexandre Courbot CC: , , , , Jon Hunter Subject: [RFC PATCH 1/7] DMA: tegra-apb: Correct runtime-pm usage Date: Tue, 18 Aug 2015 14:49:09 +0100 Message-ID: <1439905755-25150-2-git-send-email-jonathanh@nvidia.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1439905755-25150-1-git-send-email-jonathanh@nvidia.com> References: <1439905755-25150-1-git-send-email-jonathanh@nvidia.com> X-NVConfidentiality: public MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4084 Lines: 133 The tegra-apb DMA driver enables runtime-pm but never calls pm_runtime_get/put and hence the runtime-pm callbacks are never invoked. The driver manages the clocks by directly calling clk_prepare_enable() and clk_unprepare_disable(). Fix this by replacing the clk_prepare_enable() and clk_disable_unprepare() with pm_runtime_get_sync() and pm_runtime_put(), respectively. Note that the consequence of this is that if runtime-pm is disabled, then the clocks will remain on the entire time the driver is loaded. However, if runtime-pm is disabled, then power is not most likely not a concern. Signed-off-by: Jon Hunter --- drivers/dma/tegra20-apb-dma.c | 36 ++++++++++++------------------------ 1 file changed, 12 insertions(+), 24 deletions(-) diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c index c8f79dcaaee8..097432ea89fa 100644 --- a/drivers/dma/tegra20-apb-dma.c +++ b/drivers/dma/tegra20-apb-dma.c @@ -1182,14 +1182,11 @@ static int tegra_dma_alloc_chan_resources(struct dma_chan *dc) { struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc); struct tegra_dma *tdma = tdc->tdma; - int ret; dma_cookie_init(&tdc->dma_chan); tdc->config_init = false; - ret = clk_prepare_enable(tdma->dma_clk); - if (ret < 0) - dev_err(tdc2dev(tdc), "clk_prepare_enable failed: %d\n", ret); - return ret; + + return pm_runtime_get_sync(tdma->dev); } static void tegra_dma_free_chan_resources(struct dma_chan *dc) @@ -1232,7 +1229,7 @@ static void tegra_dma_free_chan_resources(struct dma_chan *dc) list_del(&sg_req->node); kfree(sg_req); } - clk_disable_unprepare(tdma->dma_clk); + pm_runtime_put(tdma->dev); tdc->slave_id = 0; } @@ -1356,21 +1353,13 @@ static int tegra_dma_probe(struct platform_device *pdev) spin_lock_init(&tdma->global_lock); pm_runtime_enable(&pdev->dev); - if (!pm_runtime_enabled(&pdev->dev)) { + if (!pm_runtime_enabled(&pdev->dev)) ret = tegra_dma_runtime_resume(&pdev->dev); - if (ret) { - dev_err(&pdev->dev, "dma_runtime_resume failed %d\n", - ret); - goto err_pm_disable; - } - } + else + ret = pm_runtime_get_sync(&pdev->dev); - /* Enable clock before accessing registers */ - ret = clk_prepare_enable(tdma->dma_clk); - if (ret < 0) { - dev_err(&pdev->dev, "clk_prepare_enable failed: %d\n", ret); + if (ret) goto err_pm_disable; - } /* Reset DMA controller */ reset_control_assert(tdma->rst); @@ -1382,7 +1371,7 @@ static int tegra_dma_probe(struct platform_device *pdev) tdma_write(tdma, TEGRA_APBDMA_CONTROL, 0); tdma_write(tdma, TEGRA_APBDMA_IRQ_MASK_SET, 0xFFFFFFFFul); - clk_disable_unprepare(tdma->dma_clk); + pm_runtime_put(&pdev->dev); INIT_LIST_HEAD(&tdma->dma_dev.channels); for (i = 0; i < cdata->nr_channels; i++) { @@ -1484,7 +1473,6 @@ err_irq: struct tegra_dma_channel *tdc = &tdma->channels[i]; tasklet_kill(&tdc->tasklet); } - err_pm_disable: pm_runtime_disable(&pdev->dev); if (!pm_runtime_status_suspended(&pdev->dev)) @@ -1543,7 +1531,7 @@ static int tegra_dma_pm_suspend(struct device *dev) int ret; /* Enable clock before accessing register */ - ret = tegra_dma_runtime_resume(dev); + ret = pm_runtime_get_sync(dev); if (ret < 0) return ret; @@ -1560,7 +1548,7 @@ static int tegra_dma_pm_suspend(struct device *dev) } /* Disable clock */ - tegra_dma_runtime_suspend(dev); + pm_runtime_put(dev); return 0; } @@ -1571,7 +1559,7 @@ static int tegra_dma_pm_resume(struct device *dev) int ret; /* Enable clock before accessing register */ - ret = tegra_dma_runtime_resume(dev); + ret = pm_runtime_get_sync(dev); if (ret < 0) return ret; @@ -1592,7 +1580,7 @@ static int tegra_dma_pm_resume(struct device *dev) } /* Disable clock */ - tegra_dma_runtime_suspend(dev); + pm_runtime_put(dev); return 0; } #endif -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/