[PATCH] i2c: designware-pci: fix autosuspend cleanup during teardown

[Guangshuo Li]

i2c_dw_pci_probe() calls pm_runtime_use_autosuspend(), but
i2c_dw_pci_remove() does not call the matching
pm_runtime_dont_use_autosuspend() during teardown.

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 teardown, this reference is not dropped.

The documentation for pm_runtime_use_autosuspend() also notes that it
is important to undo it with pm_runtime_dont_use_autosuspend() at
driver exit time, unless runtime PM was initially enabled with
devm_pm_runtime_enable().

Add the missing pm_runtime_dont_use_autosuspend() call to the driver
remove path.

This issue was found by manual code inspection.

Fixes: 18dbdda89f5c ("i2c-designware: Add runtime power management support")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Guangshuo Li <lgs201920130244@xxxxxxxxx>
---
 drivers/i2c/busses/i2c-designware-pcidrv.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/i2c/busses/i2c-designware-pcidrv.c b/drivers/i2c/busses/i2c-designware-pcidrv.c
index 468287922363..f1f4955f9a3f 100644
--- a/drivers/i2c/busses/i2c-designware-pcidrv.c
+++ b/drivers/i2c/busses/i2c-designware-pcidrv.c
@@ -300,6 +300,7 @@ static void i2c_dw_pci_remove(struct pci_dev *pdev)
 
 	i2c_dw_disable(dev);
 
+	pm_runtime_dont_use_autosuspend(device);
 	pm_runtime_forbid(device);
 	pm_runtime_get_noresume(device);
 
-- 
2.43.0