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Date: Fri, 13 Nov 2015 16:39:38 +0000
From: Jon Hunter <jonathanh@...dia.com>
To: Laxman Dewangan <ldewangan@...dia.com>,
Vinod Koul <vinod.koul@...el.com>,
Stephen Warren <swarren@...dotorg.org>,
Thierry Reding <thierry.reding@...il.com>,
Alexandre Courbot <gnurou@...il.com>
CC: <dmaengine@...r.kernel.org>, <linux-tegra@...r.kernel.org>,
<linux-kernel@...r.kernel.org>, <andy.shevchenko@...il.com>,
Jon Hunter <jonathanh@...dia.com>
Subject: [PATCH V3 1/6] 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 <jonathanh@...dia.com>
---
V3 changes:
- Removed unnecessary update to local variables in suspend/resume
V2 changes:
- Fixed return value for allocating channel
- Fixed test for return value from pm_runtime_get_sync()
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)
};
--
2.1.4
--
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