[PATCH] drivers: gpio: amd8111: Fix PCI device reference count leak

[Xiongfeng Wang <wangxiongfeng2@xxxxxxxxxx>]

for_each_pci_dev() is implemented by pci_get_device(). The comment of
pci_get_device() says that it will increase the reference count for the
returned pci_dev and also decrease the reference count for the input
pci_dev @from if it is not NULL.

If we break for_each_pci_dev() loop with pdev not NULL, we need to call
pci_dev_put() to decrease the reference count. Add the missing
pci_dev_put() after the 'out' label. Since pci_dev_put() can handle NULL
input parameter, there is no problem for the 'Device not found' branch.
For the normal path, add pci_dev_put() in amd_gpio_exit().

Fixes: f942a7de047d ("gpio: add a driver for GPIO pins found on AMD-8111 south bridge chips")
Signed-off-by: Xiongfeng Wang <wangxiongfeng2@xxxxxxxxxx>
---
 drivers/gpio/gpio-amd8111.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpio/gpio-amd8111.c b/drivers/gpio/gpio-amd8111.c
index 14e6b3e64add..6f3ded619c8b 100644
--- a/drivers/gpio/gpio-amd8111.c
+++ b/drivers/gpio/gpio-amd8111.c
@@ -226,7 +226,10 @@ static int __init amd_gpio_init(void)
 		ioport_unmap(gp.pm);
 		goto out;
 	}
+	return 0;
+
 out:
+	pci_dev_put(pdev);
 	return err;
 }
 
@@ -234,6 +237,7 @@ static void __exit amd_gpio_exit(void)
 {
 	gpiochip_remove(&gp.chip);
 	ioport_unmap(gp.pm);
+	pci_dev_put(gp.pdev);
 }
 
 module_init(amd_gpio_init);
-- 
2.20.1