From 5cb2dd32e001b0ba7dc04e0924f19d55f3cc4bac Mon Sep 17 00:00:00 2001
From: Gunar Schorcht <gunar@schorcht.net>
Date: Tue, 21 Aug 2018 09:12:25 +0200
Subject: [PATCH] drivers/enc28j60: fix of #9784

---
 drivers/enc28j60/enc28j60.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/drivers/enc28j60/enc28j60.c b/drivers/enc28j60/enc28j60.c
index 6bad0c07f927..efba924a3a95 100644
--- a/drivers/enc28j60/enc28j60.c
+++ b/drivers/enc28j60/enc28j60.c
@@ -247,6 +247,9 @@ static void mac_set(enc28j60_t *dev, uint8_t *mac)
 
 static void on_int(void *arg)
 {
+    /* disable gobal interupt enable bit to avoid loosing interupts */
+    cmd_bfc((enc28j60_t *)arg, REG_EIE, -1, EIE_INTIE);
+
     netdev_t *netdev = (netdev_t *)arg;
     netdev->event_callback(arg, NETDEV_EVENT_ISR);
 }
@@ -333,6 +336,9 @@ static int nd_recv(netdev_t *netdev, void *buf, size_t max_len, void *info)
     next = (uint16_t)((head[1] << 8) | head[0]);
     size = (uint16_t)((head[3] << 8) | head[2]) - 4;  /* discard CRC */
 
+    DEBUG("[enc28j60] recv: size=%i next=%i buf=%p len=%d\n",
+          (int)size, (int)next, buf, max_len);
+
     if (buf != NULL) {
 #ifdef MODULE_NETSTATS_L2
         netdev->stats.rx_count++;
@@ -349,6 +355,12 @@ static int nd_recv(netdev_t *netdev, void *buf, size_t max_len, void *info)
         cmd_w_addr(dev, ADDR_RX_READ, NEXT_TO_ERXRDPT(next));
         cmd_bfs(dev, REG_ECON2, -1, ECON2_PKTDEC);
     }
+    else if (max_len != 0) {
+        /* drop the packet */
+        DEBUG("[enc28j60] recv: drop packet - no buffer to receive\n");
+        cmd_w_addr(dev, ADDR_RX_READ, NEXT_TO_ERXRDPT(next));
+        cmd_bfs(dev, REG_ECON2, -1, ECON2_PKTDEC);
+    }
 
     mutex_unlock(&dev->lock);
     return (int)size;
@@ -489,6 +501,8 @@ static void nd_isr(netdev_t *netdev)
         }
         eir = cmd_rcr(dev, REG_EIR, -1);
     }
+    /* enable gobal interupt enable bit again */
+    cmd_bfs(dev, REG_EIE, -1, EIE_INTIE);
 }
 
 static int nd_get(netdev_t *netdev, netopt_t opt, void *value, size_t max_len)