driver: eth_esp32: fix shared clock check

Both MDIO and Ethernet drivers share the same clock subsystem.
After clock control update in #73807, clock_control_on()
now returns -EALREADY for already initialized clock subsystem.
As a result, ethernet driver won't initialize as needed.

Fixes #74440

Signed-off-by: Sylvio Alves <[email protected]>

Author: sylvioalves

drivers/ethernet/eth_esp32.c

@@ -212,8 +212,9 @@ int eth_esp32_initialize(const struct device *dev)
 	clock_control_subsys_t clock_subsys =
 		(clock_control_subsys_t)DT_CLOCKS_CELL(DT_NODELABEL(eth), offset);
 
+	/* clock is shared, so do not bail out if already enabled */
 	res = clock_control_on(clock_dev, clock_subsys);
-	if (res != 0) {
+	if (res < 0 && res != -EALREADY) {
 		goto err;
 	}
 

drivers/mdio/mdio_esp32.c

@@ -104,8 +104,9 @@ static int mdio_esp32_initialize(const struct device *dev)
 	clock_control_subsys_t clock_subsys =
 		(clock_control_subsys_t)DT_CLOCKS_CELL(DT_NODELABEL(mdio), offset);
 
+	/* clock is shared, so do not bail out if already enabled */
 	res = clock_control_on(clock_dev, clock_subsys);
-	if (res != 0) {
+	if (res < 0 && res != -EALREADY) {
 		goto err;
 	}