From 0633e7d14b7a891e10205a77e3e197e9cf92775d Mon Sep 17 00:00:00 2001
From: yuanjm <yuanjianmin@espressif.com>
Date: Wed, 16 Sep 2020 11:08:10 +0800
Subject: [PATCH] dhcp: Continuously try to rebind in t2 (if failed in t1)

The root cause of this issue is big UDP traffic consuming the buffer
so the DHCP doesn't have the bandwitdh to access the Tx buffer.
More info espressif/esp-lwip!217

Ref IDF-4817
---
 src/core/ipv4/dhcp.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/core/ipv4/dhcp.c b/src/core/ipv4/dhcp.c
index 79f9676c..bb4c3cde 100644
--- a/src/core/ipv4/dhcp.c
+++ b/src/core/ipv4/dhcp.c
@@ -562,6 +562,11 @@ dhcp_timeout(struct netif *netif)
       dhcp_discover(netif);
     }
   }
+#if ESP_LWIP
+  else if (dhcp->state == DHCP_STATE_REBINDING) {
+    dhcp->t2_rebind_time = 1;
+  }
+#endif /* ESP_LWIP */
 }
 
 /**