[PATCH net] Revert "mdio_bus: Remove unneeded gpiod NULL check"

[Florian Fainelli]

This reverts commit 95b80bf3db03c2bf572a357cf74b9a6aefef0a4a ("mdio_bus:
Remove unneeded gpiod NULL check"), this commit assumed that GPIOLIB
checks for NULL descriptors, so it's safe to drop them, but it is not
when CONFIG_GPIOLIB is disabled in the kernel. If we do call
gpiod_set_value_cansleep() on a GPIO descriptor we will issue warnings
coming from the inline stubs declared in include/linux/gpio/consumer.h.

Fixes: 95b80bf3db03 ("mdio_bus: Remove unneeded gpiod NULL check")
Reported-by: Woojung Huh <woojung....@microchip.com>
Signed-off-by: Florian Fainelli <f.faine...@gmail.com>
---
 drivers/net/phy/mdio_bus.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index b6f9fa670168..2df7b62c1a36 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -399,7 +399,8 @@ int __mdiobus_register(struct mii_bus *bus, struct module 
*owner)
        }
 
        /* Put PHYs in RESET to save power */
-       gpiod_set_value_cansleep(bus->reset_gpiod, 1);
+       if (bus->reset_gpiod)
+               gpiod_set_value_cansleep(bus->reset_gpiod, 1);
 
        device_del(&bus->dev);
        return err;
@@ -424,7 +425,8 @@ void mdiobus_unregister(struct mii_bus *bus)
        }
 
        /* Put PHYs in RESET to save power */
-       gpiod_set_value_cansleep(bus->reset_gpiod, 1);
+       if (bus->reset_gpiod)
+               gpiod_set_value_cansleep(bus->reset_gpiod, 1);
 
        device_del(&bus->dev);
 }
-- 
2.9.3