The pisp_be driver uses and depends on runtime_pm.
During the probe() routine, the driver needs to power up the interface
in order to identify and initialize the hardware and it later suspends
it at the end of probe().
The driver erroneously resumes the interface by calling the
pispbe_runtime_resume() function directly, without going
through the pm_runtime helpers, but later suspends it by calling
pm_runtime_put_autosuspend().
This causes a PM usage count imbalance at probe time, notified by the
runtime_pm framework with the below message in the system log:
pispbe 1000880000.pisp_be: Runtime PM usage count underflow!
Fix this by resuming the interface using the pm runtime helpers instead
of calling the resume function directly.
Fixes: 12187bd5d4f8 ("media: raspberrypi: Add support for PiSP BE")
Signed-off-by: Jacopo Mondi <jacopo.mondi@xxxxxxxxxxxxxxxx>
---
v2->v3:
- Mark pispbe_runtime_resume() as __maybe_unused as reported by
the kernel test robot <lkp@xxxxxxxxx>
- Add fixes tag
---
drivers/media/platform/raspberrypi/pisp_be/pisp_be.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/media/platform/raspberrypi/pisp_be/pisp_be.c b/drivers/media/platform/raspberrypi/pisp_be/pisp_be.c
index f42541bb4827..7b62585d7510 100644
--- a/drivers/media/platform/raspberrypi/pisp_be/pisp_be.c
+++ b/drivers/media/platform/raspberrypi/pisp_be/pisp_be.c
@@ -1638,7 +1638,7 @@ static int pispbe_runtime_suspend(struct device *dev)
return 0;
}
-static int pispbe_runtime_resume(struct device *dev)
+static int __maybe_unused pispbe_runtime_resume(struct device *dev)
{
struct pispbe_dev *pispbe = dev_get_drvdata(dev);
int ret;
@@ -1741,7 +1741,7 @@ static int pispbe_probe(struct platform_device *pdev)
pm_runtime_use_autosuspend(pispbe->dev);
pm_runtime_enable(pispbe->dev);
- ret = pispbe_runtime_resume(pispbe->dev);
+ ret = pm_runtime_resume_and_get(pispbe->dev);
if (ret)
goto pm_runtime_disable_err;
--
2.45.2
