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@xxxxxxxxxx>
---
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
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