Update vnet hardware flags if link state changes

Explains a variety of hard-to-diagnose problems with certain Atom and
Denverton NIC types.

I finally tripped over a highly-repeatable failure: home gateway
use-case bitten by refusal to negotiate a DHCP lease for the trunk
port.

The dhcp client won't send pkts unless VNET_HW_INTERFACE_FLAG_LINK_UP
is set on the tx hw interface:

  /* Interface(s) down? */
  if ((hw->flags & VNET_HW_INTERFACE_FLAG_LINK_UP) == 0)
    return;

Change-Id: I17ef2ba7b39078555fa27d2d874a60c67e1530ee
Signed-off-by: Dave Barach <dave@barachs.net>

diff --git a/src/plugins/dpdk/device/init.c b/src/plugins/dpdk/device/init.c
index 2e4c8a2..d15f5bf 100644 (file)
--- a/src/plugins/dpdk/device/init.c
+++ b/src/plugins/dpdk/device/init.c
@@ -1500,7 +1500,7 @@ dpdk_update_link_state (dpdk_device_t * xd, f64 now)
       ed->new_link_state = (u8) xd->link.link_status;
     }
 
-  if (hw_flags_chg || (xd->link.link_duplex != prev_link.link_duplex))
+  if ((xd->link.link_duplex != prev_link.link_duplex))
     {
       hw_flags_chg = 1;
       switch (xd->link.link_duplex)
@@ -1519,6 +1519,14 @@ dpdk_update_link_state (dpdk_device_t * xd, f64 now)
     vnet_hw_interface_set_link_speed (vnm, xd->hw_if_index,
                                      xd->link.link_speed * 1000);
 
+  if (xd->link.link_status != prev_link.link_status)
+    {
+      hw_flags_chg = 1;
+
+      if (xd->link.link_status)
+       hw_flags |= VNET_HW_INTERFACE_FLAG_LINK_UP;
+    }
+
   if (hw_flags_chg)
     {
       if (LINK_STATE_ELOGS)