arch/espressif: serialize Wi-Fi RX queue access.

Protect the common Espressif Wi-Fi netdev RX queue with a spinlock. The Wi-Fi RX callback enqueues packets while the netdev upper-half RX thread dequeues them, and the IOB queue helpers are not internally serialized.

Under sustained receive traffic that race can corrupt the queue state, strand IOBs, and degrade throughput over time as reported in issue #16915.

Initialize the lock during device setup and use it when clearing the queue on ifup, enqueueing received packets, and dequeuing them for the upper half.

Signed-off-by: aviralgarg05 <gargaviral99@gmail.com>

Author: aviralgarg05

arch/risc-v/src/common/espressif/esp_wlan_netdev.c

@@ -117,6 +117,7 @@ struct esp_wlan_priv_s
   struct esp_common_wifi_s *common;
   uint32_t mode;
 
+  spinlock_t rx_lock;
   netpkt_queue_t netdev_rx_queue;
   uint8_t flatbuf[CONFIG_NET_ETH_PKTSIZE];
 };
@@ -212,6 +213,7 @@ static int esp_wlan_ifup(struct netdev_lowerhalf_s *dev)
 {
   struct esp_wlan_priv_s *priv = (struct esp_wlan_priv_s *)dev;
   struct net_driver_s *netdev = &priv->dev.netdev;
+  irqstate_t flags;
   int ret = OK;
 
 #ifdef CONFIG_NET_IPv4
@@ -228,7 +230,9 @@ static int esp_wlan_ifup(struct netdev_lowerhalf_s *dev)
 
   /* Clear RX queue */
 
+  flags = spin_lock_irqsave(&priv->rx_lock);
   netpkt_free_queue(&priv->netdev_rx_queue);
+  spin_unlock_irqrestore(&priv->rx_lock, flags);
 
   /* Start Wi-Fi interface */
 
@@ -349,7 +353,13 @@ static int esp_wlan_transmit(struct netdev_lowerhalf_s *dev,
 static netpkt_t *esp_wlan_receive(struct netdev_lowerhalf_s *dev)
 {
   struct esp_wlan_priv_s *priv = (struct esp_wlan_priv_s *)dev;
-  netpkt_t *pkt = netpkt_remove_queue(&priv->netdev_rx_queue);
+  irqstate_t flags;
+  netpkt_t *pkt;
+
+  flags = spin_lock_irqsave(&priv->rx_lock);
+  pkt = netpkt_remove_queue(&priv->netdev_rx_queue);
+  spin_unlock_irqrestore(&priv->rx_lock, flags);
+
   return pkt;
 }
 
@@ -1008,6 +1018,7 @@ void IRAM_ATTR esp_wifi_tx_done_cb(uint8_t ifidx,
 static int wlan_rx_done(struct esp_wlan_priv_s *priv,
                         void *buffer, uint16_t len, void *eb)
 {
+  irqstate_t flags;
   int ret = OK;
   netpkt_t *pkt = NULL;
 
@@ -1025,7 +1036,9 @@ static int wlan_rx_done(struct esp_wlan_priv_s *priv,
       goto out;
     }
 
+  flags = spin_lock_irqsave(&priv->rx_lock);
   ret = netpkt_tryadd_queue(pkt, &priv->netdev_rx_queue);
+  spin_unlock_irqrestore(&priv->rx_lock, flags);
   if (ret < 0)
     {
       wlerr("ERROR: Failed to add packet to queue\n");
@@ -1221,6 +1234,7 @@ static int esp_wlan_initialize(uint32_t mode)
   priv->dev.rxtype           = NETDEV_RX_THREAD;
   priv->dev.priority         = 100;
 
+  spin_lock_init(&priv->rx_lock);
   IOB_QINIT(&priv->netdev_rx_queue);
 
   /* Register RX done callback. Called when the RX packet is received. */

arch/xtensa/src/common/espressif/esp_wlan_netdev.c

@@ -117,6 +117,7 @@ struct esp_wlan_priv_s
   struct esp_common_wifi_s *common;
   uint32_t mode;
 
+  spinlock_t rx_lock;
   netpkt_queue_t netdev_rx_queue;
   uint8_t flatbuf[CONFIG_NET_ETH_PKTSIZE];
 };
@@ -212,6 +213,7 @@ static int esp_wlan_ifup(struct netdev_lowerhalf_s *dev)
 {
   struct esp_wlan_priv_s *priv = (struct esp_wlan_priv_s *)dev;
   struct net_driver_s *netdev = &priv->dev.netdev;
+  irqstate_t flags;
   int ret = OK;
 
 #ifdef CONFIG_NET_IPv4
@@ -228,7 +230,9 @@ static int esp_wlan_ifup(struct netdev_lowerhalf_s *dev)
 
   /* Clear RX queue */
 
+  flags = spin_lock_irqsave(&priv->rx_lock);
   netpkt_free_queue(&priv->netdev_rx_queue);
+  spin_unlock_irqrestore(&priv->rx_lock, flags);
 
   /* Start Wi-Fi interface */
 
@@ -349,7 +353,13 @@ static int esp_wlan_transmit(struct netdev_lowerhalf_s *dev,
 static netpkt_t *esp_wlan_receive(struct netdev_lowerhalf_s *dev)
 {
   struct esp_wlan_priv_s *priv = (struct esp_wlan_priv_s *)dev;
-  netpkt_t *pkt = netpkt_remove_queue(&priv->netdev_rx_queue);
+  irqstate_t flags;
+  netpkt_t *pkt;
+
+  flags = spin_lock_irqsave(&priv->rx_lock);
+  pkt = netpkt_remove_queue(&priv->netdev_rx_queue);
+  spin_unlock_irqrestore(&priv->rx_lock, flags);
+
   return pkt;
 }
 
@@ -1008,6 +1018,7 @@ void IRAM_ATTR esp_wifi_tx_done_cb(uint8_t ifidx,
 static int wlan_rx_done(struct esp_wlan_priv_s *priv,
                         void *buffer, uint16_t len, void *eb)
 {
+  irqstate_t flags;
   int ret = OK;
   netpkt_t *pkt = NULL;
 
@@ -1025,7 +1036,9 @@ static int wlan_rx_done(struct esp_wlan_priv_s *priv,
       goto out;
     }
 
+  flags = spin_lock_irqsave(&priv->rx_lock);
   ret = netpkt_tryadd_queue(pkt, &priv->netdev_rx_queue);
+  spin_unlock_irqrestore(&priv->rx_lock, flags);
   if (ret != OK)
     {
       wlerr("ERROR: Failed to add packet to queue\n");
@@ -1224,6 +1237,7 @@ static int esp_wlan_initialize(uint32_t mode)
   priv->dev.rxtype           = NETDEV_RX_THREAD;
   priv->dev.priority         = 100;
 
+  spin_lock_init(&priv->rx_lock);
   IOB_QINIT(&priv->netdev_rx_queue);
 
   /* Register RX done callback. Called when the RX packet is received. */