Hi Jacopo,
Thank you for this fix.
On Tue, 17 Jun 2025 at 14:54, Jacopo Mondi jacopo.mondi@ideasonboard.com wrote:
During the probe() routine, the PiSP BE driver needs to power up the interface in order to identify and initialize the hardware.
The driver 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 and use the pm_runtime framework in the probe() error path. While at it, remove manual suspend of the interface in the remove() function. The driver cannot be unloaded if in use, so simply disable runtime pm.
To simplify the implementation, make the driver depend on PM as the RPI5 platform where the ISP is integrated in uses the PM framework by default.
Fixes: 12187bd5d4f8 ("media: raspberrypi: Add support for PiSP BE") Cc: stable@vger.kernel.org Reviewed-by: Laurent Pinchart laurent.pinchart@ideasonboard.com Signed-off-by: Jacopo Mondi jacopo.mondi@ideasonboard.com
Tested-by: Naushir Patuck naush@raspberrypi.com Reviewed-by: Naushir Patuck naush@raspberrypi.com
drivers/media/platform/raspberrypi/pisp_be/Kconfig | 1 + drivers/media/platform/raspberrypi/pisp_be/pisp_be.c | 5 ++--- 2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/media/platform/raspberrypi/pisp_be/Kconfig b/drivers/media/platform/raspberrypi/pisp_be/Kconfig index 46765a2e4c4d1573757ff842f208834216e582cb..a9e51fd94aadc6add70f883bfcea0c9fa91f0c4b 100644 --- a/drivers/media/platform/raspberrypi/pisp_be/Kconfig +++ b/drivers/media/platform/raspberrypi/pisp_be/Kconfig @@ -3,6 +3,7 @@ config VIDEO_RASPBERRYPI_PISP_BE depends on V4L_PLATFORM_DRIVERS depends on VIDEO_DEV depends on ARCH_BCM2835 || COMPILE_TEST
depends on PM select VIDEO_V4L2_SUBDEV_API select MEDIA_CONTROLLER select VIDEOBUF2_DMA_CONTIGdiff --git a/drivers/media/platform/raspberrypi/pisp_be/pisp_be.c b/drivers/media/platform/raspberrypi/pisp_be/pisp_be.c index ccc6cb99868b842ac0d295f9ec28470303e60788..be794a12362020f42b3cf5bd291b4a1625543b5f 100644 --- a/drivers/media/platform/raspberrypi/pisp_be/pisp_be.c +++ b/drivers/media/platform/raspberrypi/pisp_be/pisp_be.c @@ -1725,7 +1725,7 @@ 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;@@ -1747,7 +1747,7 @@ static int pispbe_probe(struct platform_device *pdev) disable_devs_err: pispbe_destroy_devices(pispbe); pm_runtime_suspend_err:
pispbe_runtime_suspend(pispbe->dev);
pm_runtime_put(pispbe->dev);pm_runtime_disable_err: pm_runtime_dont_use_autosuspend(pispbe->dev); pm_runtime_disable(pispbe->dev); @@ -1761,7 +1761,6 @@ static void pispbe_remove(struct platform_device *pdev)
pispbe_destroy_devices(pispbe);
pispbe_runtime_suspend(pispbe->dev); pm_runtime_dont_use_autosuspend(pispbe->dev); pm_runtime_disable(pispbe->dev);}
-- 2.49.0