nfc: pn533: pn533_phy_ops dev_[up, down] return int

Change dev_up and dev_down functions of struct pn533_phy_ops to return
int. This way the pn533 core can report errors in the phy layer to upper
layers.
The only user of this is currently uart.c and it is changed to report
the error of a possibly failing call to serdev_device_open.

Reported-by: coverity-bot <keescook+coverity-bot@chromium.org>
Addresses-Coverity-ID: 1487395 ("Error handling issues")
Fixes: c656aa4 ("nfc: pn533: add UART phy driver")
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/nfc/pn533/pn533.c

@@ -2643,13 +2643,17 @@ static int pn532_sam_configuration(struct nfc_dev *nfc_dev)
 static int pn533_dev_up(struct nfc_dev *nfc_dev)
 {
 	struct pn533 *dev = nfc_get_drvdata(nfc_dev);
+	int rc;
 
-	if (dev->phy_ops->dev_up)
-		dev->phy_ops->dev_up(dev);
+	if (dev->phy_ops->dev_up) {
+		rc = dev->phy_ops->dev_up(dev);
+		if (rc)
+			return rc;
+	}
 
 	if ((dev->device_type == PN533_DEVICE_PN532) ||
 		(dev->device_type == PN533_DEVICE_PN532_AUTOPOLL)) {
-		int rc = pn532_sam_configuration(nfc_dev);
+		rc = pn532_sam_configuration(nfc_dev);
 
 		if (rc)
 			return rc;
@@ -2665,7 +2669,7 @@ static int pn533_dev_down(struct nfc_dev *nfc_dev)
 
 	ret = pn533_rf_field(nfc_dev, 0);
 	if (dev->phy_ops->dev_down && !ret)
-		dev->phy_ops->dev_down(dev);
+		ret = dev->phy_ops->dev_down(dev);
 
 	return ret;
 }

drivers/nfc/pn533/pn533.h

@@ -224,8 +224,8 @@ struct pn533_phy_ops {
 	 * bring up it's interface to the chip and have it suspended for power
 	 * saving reasons otherwise.
 	 */
-	void (*dev_up)(struct pn533 *priv);
-	void (*dev_down)(struct pn533 *priv);
+	int (*dev_up)(struct pn533 *priv);
+	int (*dev_down)(struct pn533 *priv);
 };
 
 

drivers/nfc/pn533/uart.c

@@ -100,20 +100,27 @@ static void pn532_uart_abort_cmd(struct pn533 *dev, gfp_t flags)
 	pn533_recv_frame(dev, NULL, -ENOENT);
 }
 
-static void pn532_dev_up(struct pn533 *dev)
+static int pn532_dev_up(struct pn533 *dev)
 {
 	struct pn532_uart_phy *pn532 = dev->phy;
+	int ret = 0;
+
+	ret = serdev_device_open(pn532->serdev);
+	if (ret)
+		return ret;
 
-	serdev_device_open(pn532->serdev);
 	pn532->send_wakeup = PN532_SEND_LAST_WAKEUP;
+	return ret;
 }
 
-static void pn532_dev_down(struct pn533 *dev)
+static int pn532_dev_down(struct pn533 *dev)
 {
 	struct pn532_uart_phy *pn532 = dev->phy;
 
 	serdev_device_close(pn532->serdev);
 	pn532->send_wakeup = PN532_SEND_WAKEUP;
+
+	return 0;
 }
 
 static struct pn533_phy_ops uart_phy_ops = {