realtek: Indicate that RTL8231 LED ops can sleep

The RTL8231 LED driver is using the .brightness_set op, which according
to the documentation should not sleep. Since the RTL8231 is controlled
via an MDIO bus, this is not the case.

When using a non-offloaded LED driver such as netdev, this may currently
trigger kernel warnings:
    WARNING: CPU: 0 PID: 14 at kernel/time/timer.c:1754 call_timer_fn.isra.0+0x84/0x8c
    timer: led_timer_function+0x0/0x1d8 preempt leak: 00000100 -> 00000000

Switch to the .brightness_set_blocking op to indicate the operation
might sleep.

Fixes: 6ef6014 ("realtek: Add pinctrl support for RTL8231")
Signed-off-by: Sander Vanheule <sander@svanheule.net>

Author: svanheule

target/linux/realtek/patches-6.12/804-leds-Add-support-for-RTL8231-LED-scan-matrix.patch

@@ -129,15 +129,15 @@ Signed-off-by: Sander Vanheule <sander@svanheule.net>
 +	.toggle_rates = rtl8231_toggle_rates,
 +};
 +
-+static void rtl8231_led_brightness_set(struct led_classdev *led_cdev,
++static int rtl8231_led_brightness_set(struct led_classdev *led_cdev,
 +	enum led_brightness brightness)
 +{
 +	struct rtl8231_led *pled = to_rtl8231_led(led_cdev);
 +
 +	if (brightness)
-+		regmap_field_write(pled->reg_field, pled->modes->on);
++		return regmap_field_write(pled->reg_field, pled->modes->on);
 +	else
-+		regmap_field_write(pled->reg_field, pled->modes->off);
++		return regmap_field_write(pled->reg_field, pled->modes->off);
 +}
 +
 +static enum led_brightness rtl8231_led_brightness_get(struct led_classdev *led_cdev)
@@ -276,7 +276,7 @@ Signed-off-by: Sander Vanheule <sander@svanheule.net>
 +
 +	pled->led.max_brightness = 1;
 +	pled->led.brightness_get = rtl8231_led_brightness_get;
-+	pled->led.brightness_set = rtl8231_led_brightness_set;
++	pled->led.brightness_set_blocking = rtl8231_led_brightness_set;
 +	pled->led.blink_set = rtl8231_led_blink_set;
 +
 +	init_data.fwnode = fwnode;

target/linux/realtek/patches-6.18/804-leds-Add-support-for-RTL8231-LED-scan-matrix.patch

@@ -129,15 +129,15 @@ Signed-off-by: Sander Vanheule <sander@svanheule.net>
 +	.toggle_rates = rtl8231_toggle_rates,
 +};
 +
-+static void rtl8231_led_brightness_set(struct led_classdev *led_cdev,
++static int rtl8231_led_brightness_set(struct led_classdev *led_cdev,
 +	enum led_brightness brightness)
 +{
 +	struct rtl8231_led *pled = to_rtl8231_led(led_cdev);
 +
 +	if (brightness)
-+		regmap_field_write(pled->reg_field, pled->modes->on);
++		return regmap_field_write(pled->reg_field, pled->modes->on);
 +	else
-+		regmap_field_write(pled->reg_field, pled->modes->off);
++		return regmap_field_write(pled->reg_field, pled->modes->off);
 +}
 +
 +static enum led_brightness rtl8231_led_brightness_get(struct led_classdev *led_cdev)
@@ -276,7 +276,7 @@ Signed-off-by: Sander Vanheule <sander@svanheule.net>
 +
 +	pled->led.max_brightness = 1;
 +	pled->led.brightness_get = rtl8231_led_brightness_get;
-+	pled->led.brightness_set = rtl8231_led_brightness_set;
++	pled->led.brightness_set_blocking = rtl8231_led_brightness_set;
 +	pled->led.blink_set = rtl8231_led_blink_set;
 +
 +	init_data.fwnode = fwnode;