[PATCH] Bluetooth: btmtksdio: fix usage_count leak when autosuspend_delay is negative

[Guangshuo Li]

btmtksdio_setup() calls pm_runtime_use_autosuspend() when runtime PM
is supported, but btmtksdio_remove() does not call the matching
pm_runtime_dont_use_autosuspend() when removing the device.

If the autosuspend delay is set to a negative value while autosuspend
is enabled, the runtime PM core increments usage_count to prevent
runtime suspend. Without calling pm_runtime_dont_use_autosuspend()
during driver teardown, this reference is not dropped and usage_count
remains unbalanced.

Add the missing pm_runtime_dont_use_autosuspend() call in the remove
path before restoring the runtime PM usage reference.

This issue was found by manual code inspection.

Fixes: 7f3c563c575e ("Bluetooth: btmtksdio: Add runtime PM support to SDIO based Bluetooth")
Signed-off-by: Guangshuo Li <lgs201920130244 at gmail.com>
---
 drivers/bluetooth/btmtksdio.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/bluetooth/btmtksdio.c b/drivers/bluetooth/btmtksdio.c
index c6f80c419e90..4e1012e90979 100644
--- a/drivers/bluetooth/btmtksdio.c
+++ b/drivers/bluetooth/btmtksdio.c
@@ -1480,6 +1480,9 @@ static void btmtksdio_remove(struct sdio_func *func)
 	if (test_bit(BTMTKSDIO_FUNC_ENABLED, &bdev->tx_state))
 		btmtksdio_close(hdev);
 
+	if (bdev->data->pm_runtime_supported)
+		pm_runtime_dont_use_autosuspend(bdev->dev);
+
 	/* Be consistent the state in btmtksdio_probe */
 	pm_runtime_get_noresume(bdev->dev);
 
-- 
2.43.0