[PATCH 6.19 542/844] media: chips-media: wave5: Fix PM runtime usage count underflow

From: Sasha Levin

Date: Sat Feb 28 2026 - 15:32:50 EST


From: Xulin Sun <xulin.sun@xxxxxxxxxxxxx>

[ Upstream commit 9cf4452e824c1e2d41c9c0b13cc8a32a0a7dec38 ]

Replace pm_runtime_put_sync() with pm_runtime_dont_use_autosuspend() in
the remove path to properly pair with pm_runtime_use_autosuspend() from
probe. This allows pm_runtime_disable() to handle reference count cleanup
correctly regardless of current suspend state.

The driver calls pm_runtime_put_sync() unconditionally in remove, but the
device may already be suspended due to autosuspend configured in probe.
When autosuspend has already suspended the device, the usage count is 0,
and pm_runtime_put_sync() decrements it to -1.

This causes the following warning on module unload:

------------[ cut here ]------------
WARNING: CPU: 1 PID: 963 at kernel/kthread.c:1430
kthread_destroy_worker+0x84/0x98
...
vdec 30210000.video-codec: Runtime PM usage count underflow!

Fixes: 9707a6254a8a ("media: chips-media: wave5: Add the v4l2 layer")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Xulin Sun <xulin.sun@xxxxxxxxxxxxx>
Reviewed-by: Nicolas Dufresne <nicolas.dufresne@xxxxxxxxxxxxx>
Signed-off-by: Nicolas Dufresne <nicolas.dufresne@xxxxxxxxxxxxx>
Signed-off-by: Hans Verkuil <hverkuil+cisco@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/media/platform/chips-media/wave5/wave5-vpu.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/media/platform/chips-media/wave5/wave5-vpu.c b/drivers/media/platform/chips-media/wave5/wave5-vpu.c
index e1715d3f43b0d..23aa3ab51a0ef 100644
--- a/drivers/media/platform/chips-media/wave5/wave5-vpu.c
+++ b/drivers/media/platform/chips-media/wave5/wave5-vpu.c
@@ -356,7 +356,7 @@ static void wave5_vpu_remove(struct platform_device *pdev)
hrtimer_cancel(&dev->hrtimer);
}

- pm_runtime_put_sync(&pdev->dev);
+ pm_runtime_dont_use_autosuspend(&pdev->dev);
pm_runtime_disable(&pdev->dev);

mutex_destroy(&dev->dev_lock);
--
2.51.0