can: mcp251x: add error handling for power enable in open and resume

Add missing error handling for mcp251x_power_enable() calls in both
mcp251x_open() and mcp251x_can_resume() functions.

In mcp251x_open(), if power enable fails, jump to error path to close
candev without attempting to disable power again.

In mcp251x_can_resume(), properly check return values of power enable calls
for both power and transceiver regulators. If any fails, return the error
code to the PM framework and log the failure.

This ensures the driver properly handles power control failures and
maintains correct device state.

Signed-off-by: Wenyuan Li <[email protected]>
Link: https://patch.msgid.link/[email protected]
[mkl: fix patch description]
[mkl: mcp251x_can_resume(): replace goto by return]
Signed-off-by: Marc Kleine-Budde <[email protected]>

Author: vanyuan599

drivers/net/can/spi/mcp251x.c

@@ -1225,7 +1225,11 @@ static int mcp251x_open(struct net_device *net)
 	}
 
 	mutex_lock(&priv->mcp_lock);
-	mcp251x_power_enable(priv->transceiver, 1);
+	ret = mcp251x_power_enable(priv->transceiver, 1);
+	if (ret) {
+		dev_err(&spi->dev, "failed to enable transceiver power: %pe\n", ERR_PTR(ret));
+		goto out_close_candev;
+	}
 
 	priv->force_quit = 0;
 	priv->tx_skb = NULL;
@@ -1272,6 +1276,7 @@ static int mcp251x_open(struct net_device *net)
 	mcp251x_hw_sleep(spi);
 out_close:
 	mcp251x_power_enable(priv->transceiver, 0);
+out_close_candev:
 	close_candev(net);
 	mutex_unlock(&priv->mcp_lock);
 	if (release_irq)
@@ -1516,11 +1521,25 @@ static int __maybe_unused mcp251x_can_resume(struct device *dev)
 {
 	struct spi_device *spi = to_spi_device(dev);
 	struct mcp251x_priv *priv = spi_get_drvdata(spi);
+	int ret = 0;
 
-	if (priv->after_suspend & AFTER_SUSPEND_POWER)
-		mcp251x_power_enable(priv->power, 1);
-	if (priv->after_suspend & AFTER_SUSPEND_UP)
-		mcp251x_power_enable(priv->transceiver, 1);
+	if (priv->after_suspend & AFTER_SUSPEND_POWER) {
+		ret = mcp251x_power_enable(priv->power, 1);
+		if (ret) {
+			dev_err(dev, "failed to restore power: %pe\n", ERR_PTR(ret));
+			return ret;
+		}
+	}
+
+	if (priv->after_suspend & AFTER_SUSPEND_UP) {
+		ret = mcp251x_power_enable(priv->transceiver, 1);
+		if (ret) {
+			dev_err(dev, "failed to restore transceiver power: %pe\n", ERR_PTR(ret));
+			if (priv->after_suspend & AFTER_SUSPEND_POWER)
+				mcp251x_power_enable(priv->power, 0);
+			return ret;
+		}
+	}
 
 	if (priv->after_suspend & (AFTER_SUSPEND_POWER | AFTER_SUSPEND_UP))
 		queue_work(priv->wq, &priv->restart_work);