Update `lan78xx_irq_bus_sync_unlock` to handle errors in register
read/write operations. If an error occurs, log it and exit the function
appropriately.  This ensures proper handling of failures during IRQ
synchronization.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
---
 drivers/net/usb/lan78xx.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/net/usb/lan78xx.c b/drivers/net/usb/lan78xx.c
index 2d16c1fc850e..2ae9565b5044 100644
--- a/drivers/net/usb/lan78xx.c
+++ b/drivers/net/usb/lan78xx.c
@@ -2382,13 +2382,22 @@ static void lan78xx_irq_bus_sync_unlock(struct irq_data *irqd)
 	struct lan78xx_net *dev =
 			container_of(data, struct lan78xx_net, domain_data);
 	u32 buf;
+	int ret;
 
 	/* call register access here because irq_bus_lock & irq_bus_sync_unlock
 	 * are only two callbacks executed in non-atomic contex.
 	 */
-	lan78xx_read_reg(dev, INT_EP_CTL, &buf);
+	ret = lan78xx_read_reg(dev, INT_EP_CTL, &buf);
+	if (ret < 0)
+		goto irq_bus_sync_unlock;
+
 	if (buf != data->irqenable)
-		lan78xx_write_reg(dev, INT_EP_CTL, data->irqenable);
+		ret = lan78xx_write_reg(dev, INT_EP_CTL, data->irqenable);
+
+irq_bus_sync_unlock:
+	if (ret < 0)
+		netdev_err(dev->net, "Failed to sync IRQ enable register: %pe\n",
+			   ERR_PTR(ret));
 
 	mutex_unlock(&data->irq_lock);
 }
-- 
2.39.5