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dmaengine: tegra-apb: Correct runtime-pm usage

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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 <jonathanh@nvidia.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
This commit is contained in:
Jon Hunter 2015-11-13 16:39:38 +00:00 committed by Vinod Koul
parent 8005c49d9a
commit edd3bdbe9d
1 changed files with 18 additions and 25 deletions
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43
drivers/dma/tegra20-apb-dma.c
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@ -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)
};