dmaengine: qcom: bam_dma: check if the runtime pm enabled

Message ID 20180514161852.9620-1-srinivas.kandagatla@linaro.org
State New
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Series
  • dmaengine: qcom: bam_dma: check if the runtime pm enabled
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Commit Message

Srinivas Kandagatla May 14, 2018, 4:18 p.m.
Disabling pm runtime at probe is not sufficient to get BAM working
on remotely controller instances. pm_runtime_get_sync() would return
-EACCES in such cases.
So check if runtime pm is enabled before returning error from bam functions.

Fixes: 5b4a68952a89 ("dmaengine: qcom: bam_dma: disable runtime pm on remote controlled")
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>

---
 drivers/dma/qcom/bam_dma.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

-- 
2.16.2

Comments

Srinivas Kandagatla May 17, 2018, 9:20 a.m. | #1
On 17/05/18 06:21, Vinod wrote:
> On 14-05-18, 17:18, Srinivas Kandagatla wrote:

>> Disabling pm runtime at probe is not sufficient to get BAM working

>> on remotely controller instances. pm_runtime_get_sync() would return

>> -EACCES in such cases.

>> So check if runtime pm is enabled before returning error from bam functions.

>>

>> Fixes: 5b4a68952a89 ("dmaengine: qcom: bam_dma: disable runtime pm on remote controlled")

>> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>

>> ---

>>   drivers/dma/qcom/bam_dma.c | 10 +++++-----

>>   1 file changed, 5 insertions(+), 5 deletions(-)

>>

>> diff --git a/drivers/dma/qcom/bam_dma.c b/drivers/dma/qcom/bam_dma.c

>> index d29275b97e84..5f4babebc508 100644

>> --- a/drivers/dma/qcom/bam_dma.c

>> +++ b/drivers/dma/qcom/bam_dma.c

>> @@ -540,7 +540,7 @@ static void bam_free_chan(struct dma_chan *chan)

>>   	int ret;

>>   

>>   	ret = pm_runtime_get_sync(bdev->dev);

>> -	if (ret < 0)

>> +	if (pm_runtime_enabled(bdev->dev) && ret < 0)

> 

> would it make sense to first check enabled and do _get_sync()

>

Both of them check the disable_depth, however doing it the way you 
suggested would avoid some additional calls.

>          if (pm_runtime_enabled()) {

>                  ret = pm_runtime_get_sync() {

>                  ...

>                  }

>          }

sound like good idea!
> 

Just noticed that some of the drivers use:

         err = pm_runtime_get_sync(dev);
         if (err < 0 && err !=-EACCES)
		return;

others warp up this into local function.

Will send a v2!


thanks,
srini

> thus making clear in code that we do calls only when it is enabled. Also you can

> add a local macro for this code and use that rather than copy pasting :)

>

Patch

diff --git a/drivers/dma/qcom/bam_dma.c b/drivers/dma/qcom/bam_dma.c
index d29275b97e84..5f4babebc508 100644
--- a/drivers/dma/qcom/bam_dma.c
+++ b/drivers/dma/qcom/bam_dma.c
@@ -540,7 +540,7 @@  static void bam_free_chan(struct dma_chan *chan)
 	int ret;
 
 	ret = pm_runtime_get_sync(bdev->dev);
-	if (ret < 0)
+	if (pm_runtime_enabled(bdev->dev) && ret < 0)
 		return;
 
 	vchan_free_chan_resources(to_virt_chan(chan));
@@ -721,7 +721,7 @@  static int bam_pause(struct dma_chan *chan)
 	int ret;
 
 	ret = pm_runtime_get_sync(bdev->dev);
-	if (ret < 0)
+	if (pm_runtime_enabled(bdev->dev) && ret < 0)
 		return ret;
 
 	spin_lock_irqsave(&bchan->vc.lock, flag);
@@ -747,7 +747,7 @@  static int bam_resume(struct dma_chan *chan)
 	int ret;
 
 	ret = pm_runtime_get_sync(bdev->dev);
-	if (ret < 0)
+	if (pm_runtime_enabled(bdev->dev) && ret < 0)
 		return ret;
 
 	spin_lock_irqsave(&bchan->vc.lock, flag);
@@ -853,7 +853,7 @@  static irqreturn_t bam_dma_irq(int irq, void *data)
 		tasklet_schedule(&bdev->task);
 
 	ret = pm_runtime_get_sync(bdev->dev);
-	if (ret < 0)
+	if (pm_runtime_enabled(bdev->dev) && ret < 0)
 		return ret;
 
 	if (srcs & BAM_IRQ) {
@@ -970,7 +970,7 @@  static void bam_start_dma(struct bam_chan *bchan)
 		return;
 
 	ret = pm_runtime_get_sync(bdev->dev);
-	if (ret < 0)
+	if (pm_runtime_enabled(bdev->dev) && ret < 0)
 		return;
 
 	while (vd && !IS_BUSY(bchan)) {