From edd3bdbe9db1415f744bb5da0752675ddbd9eee0 Mon Sep 17 00:00:00 2001 From: Jon Hunter Date: Fri, 13 Nov 2015 16:39:38 +0000 Subject: [PATCH] dmaengine: tegra-apb: Correct runtime-pm usage 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 Signed-off-by: Vinod Koul --- drivers/dma/tegra20-apb-dma.c | 43 +++++++++++++++-------------------- 1 file changed, 18 insertions(+), 25 deletions(-) diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c index c8f79dcaaee8..f68bccf55a24 100644 --- a/drivers/dma/tegra20-apb-dma.c +++ b/drivers/dma/tegra20-apb-dma.c @@ -1186,10 +1186,12 @@ static int tegra_dma_alloc_chan_resources(struct dma_chan *dc) dma_cookie_init(&tdc->dma_chan); tdc->config_init = false; - ret = clk_prepare_enable(tdma->dma_clk); + + ret = pm_runtime_get_sync(tdma->dev); if (ret < 0) - dev_err(tdc2dev(tdc), "clk_prepare_enable failed: %d\n", ret); - return ret; + return ret; + + return 0; } static void tegra_dma_free_chan_resources(struct dma_chan *dc) @@ -1232,7 +1234,7 @@ 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; } @@ -1356,20 +1358,14 @@ 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); - goto err_pm_disable; + pm_runtime_disable(&pdev->dev); + return ret; } /* Reset DMA controller */ @@ -1382,7 +1378,7 @@ 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++) { @@ -1485,7 +1481,6 @@ err_irq: tasklet_kill(&tdc->tasklet); } -err_pm_disable: pm_runtime_disable(&pdev->dev); if (!pm_runtime_status_suspended(&pdev->dev)) tegra_dma_runtime_suspend(&pdev->dev); @@ -1543,7 +1538,7 @@ 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 +1555,7 @@ static int tegra_dma_pm_suspend(struct device *dev) } /* Disable clock */ - tegra_dma_runtime_suspend(dev); + pm_runtime_put(dev); return 0; } @@ -1571,7 +1566,7 @@ 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; @@ -1592,16 +1587,14 @@ static int tegra_dma_pm_resume(struct device *dev) } /* Disable clock */ - tegra_dma_runtime_suspend(dev); + pm_runtime_put(dev); return 0; } #endif static const struct dev_pm_ops tegra_dma_dev_pm_ops = { -#ifdef CONFIG_PM - .runtime_suspend = tegra_dma_runtime_suspend, - .runtime_resume = tegra_dma_runtime_resume, -#endif + SET_RUNTIME_PM_OPS(tegra_dma_runtime_suspend, tegra_dma_runtime_resume, + NULL) SET_SYSTEM_SLEEP_PM_OPS(tegra_dma_pm_suspend, tegra_dma_pm_resume) }; -- 2.20.1