[PATCH v3 net] net: systemport: Add error pointer checks in bcm_sysport_map_queues() and bcm_sysport_unmap_queues()

[Dipendra Khadka <kdipendra88@gmail.com>]

Add error pointer checks in bcm_sysport_map_queues() and
bcm_sysport_unmap_queues() after calling dsa_port_from_netdev().

Fixes: d156576362c0 ("net: systemport: Establish lower/upper queue mapping")
Fixes: da106a140f9c ("net: systemport: Unmap queues upon DSA unregister event")
Signed-off-by: Dipendra Khadka <kdipendra88@gmail.com>
---
v3:
 - Updated patch subject
 - Updated patch description
 - Added Fixes: tags
 - Fixed typo from PRT_ERR to PTR_ERR
 - Error is checked just after  assignment
v2: https://lore.kernel.org/all/20240923053900.1310-1-kdipendra88@gmail.com/
 - Change the subject of the patch to net
v1: https://lore.kernel.org/all/20240922181739.50056-1-kdipendra88@gmail.com/
 drivers/net/ethernet/broadcom/bcmsysport.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/bcmsysport.c b/drivers/net/ethernet/broadcom/bcmsysport.c
index c9faa8540859..493702fdabc3 100644
--- a/drivers/net/ethernet/broadcom/bcmsysport.c
+++ b/drivers/net/ethernet/broadcom/bcmsysport.c
@@ -2331,11 +2331,15 @@ static const struct net_device_ops bcm_sysport_netdev_ops = {
 static int bcm_sysport_map_queues(struct net_device *dev,
 				  struct net_device *slave_dev)
 {
-	struct dsa_port *dp = dsa_port_from_netdev(slave_dev);
 	struct bcm_sysport_priv *priv = netdev_priv(dev);
 	struct bcm_sysport_tx_ring *ring;
 	unsigned int num_tx_queues;
 	unsigned int q, qp, port;
+	struct dsa_port *dp;
+
+	dp = dsa_port_from_netdev(slave_dev);
+	if (IS_ERR(dp))
+		return PTR_ERR(dp);
 
 	/* We can't be setting up queue inspection for non directly attached
 	 * switches
@@ -2386,11 +2390,15 @@ static int bcm_sysport_map_queues(struct net_device *dev,
 static int bcm_sysport_unmap_queues(struct net_device *dev,
 				    struct net_device *slave_dev)
 {
-	struct dsa_port *dp = dsa_port_from_netdev(slave_dev);
 	struct bcm_sysport_priv *priv = netdev_priv(dev);
 	struct bcm_sysport_tx_ring *ring;
 	unsigned int num_tx_queues;
 	unsigned int q, qp, port;
+	struct dsa_port *dp;
+
+	dp = dsa_port_from_netdev(slave_dev);
+	if (IS_ERR(dp))
+		return PTR_ERR(dp);
 
 	port = dp->index;
 
-- 
2.43.0