media: chips-media: wave5: Fix PM runtime usage count underflow

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@vger.kernel.org
Signed-off-by: Xulin Sun <xulin.sun@windriver.com>
Reviewed-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Signed-off-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>

diff --git a/drivers/media/platform/chips-media/wave5/wave5-vpu.c b/drivers/media/platform/chips-media/wave5/wave5-vpu.c
index e1715d3f43b0d803fef061603f029cb16a4efec1..23aa3ab51a0ef9788673e88b0c380d08096cdda5 100644 (file)
--- 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);