Enable runtime pm and use pm_runtime_get_sync and pm_runtime_put
for OMAP DMA driver.
Since DMA driver callback will happen from interrupt context and
DMA client driver will release all DMA resources from interrupt
context itself, pm_runtime_put_sync() cannot be used in DMA driver.
Instead, pm_runtime_put() is used which is asynchronous call and
gets executed in work queue.
Signed-off-by: G, Manjunath Kondaiah <manjugk@xxxxxx>
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: Kevin Hilman <khilman@xxxxxxxxxxxxxxxxxxx>
Cc: Tony Lindgren <tony@xxxxxxxxxxx>
Cc: Santosh Shilimkar <santosh.shilimkar@xxxxxx>
Cc: Benoit Cousson <b-cousson@xxxxxx>
---
arch/arm/plat-omap/dma.c | 15 +++++++++++++++
1 files changed, 15 insertions(+), 0 deletions(-)
diff --git a/arch/arm/plat-omap/dma.c b/arch/arm/plat-omap/dma.c
index a859c70..527ebfc 100644
--- a/arch/arm/plat-omap/dma.c
+++ b/arch/arm/plat-omap/dma.c
@@ -32,6 +32,7 @@
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/delay.h>
+#include <linux/pm_runtime.h>
#include <plat/dma.h>
#include <plat/tc.h>
@@ -302,6 +303,7 @@ int omap_request_dma(int dev_id, const char *dev_name,
unsigned long flags;
struct omap_dma_lch *chan;
+ pm_runtime_get_sync(&pd->dev);
spin_lock_irqsave(&dma_chan_lock, flags);
for (ch = 0; ch < dma_chan_count; ch++) {
if (free_ch == -1 && dma_chan[ch].dev_id == -1) {
@@ -312,6 +314,7 @@ int omap_request_dma(int dev_id, const char *dev_name,
}
if (free_ch == -1) {
spin_unlock_irqrestore(&dma_chan_lock, flags);
+ pm_runtime_put(&pd->dev);
return -EBUSY;
}
chan = dma_chan + free_ch;
@@ -403,6 +406,7 @@ void omap_free_dma(int lch)
omap_clear_dma(lch);
p->clear_sglist_mode(lch);
}
+ pm_runtime_put(&pd->dev);
spin_lock_irqsave(&dma_chan_lock, flags);
dma_chan[lch].dev_id = -1;
dma_chan[lch].next_lch = -1;
@@ -734,6 +738,9 @@ static int __devinit omap_system_dma_probe(struct platform_device *pdev)
dma_chan = d->chan;
enable_1510_mode = d->dev_caps & ENABLE_1510_MODE;
+ pm_runtime_enable(&pd->dev);
+ pm_runtime_get_sync(&pd->dev);
+
spin_lock_init(&dma_chan_lock);
for (ch = 0; ch < dma_chan_count; ch++) {
unsigned long flags;
@@ -760,6 +767,14 @@ static int __devinit omap_system_dma_probe(struct platform_device *pdev)
dma_chan[1].dev_id = 1;
}
p->show_dma_caps();
+
+ /*
+ * Note: If dma channels are reserved through boot paramters,
+ * then dma device is always enabled.
+ */
+ if (!omap_dma_reserve_channels)
+ pm_runtime_put(&pd->dev);
+
return 0;
}
--
1.7.1
--
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