e1000: add interrupt limitations in guide

Update interrupt related limitations for e1000em nic.
It only support one interrupt source and not support auto-clear.

Signed-off-by: Marvin Liu <yong.liu@intel.com>
Acked-by: John McNamara <john.mcnamara@intel.com>

diff --git a/doc/guides/nics/e1000em.rst b/doc/guides/nics/e1000em.rst
index fedafad..265b147 100644 (file)
--- a/doc/guides/nics/e1000em.rst
+++ b/doc/guides/nics/e1000em.rst
@@ -176,3 +176,7 @@ The following are known limitations:
     testpmd [options] -- --mbuf-size=<your-max-packet-size>
 
 #.  Qemu e1000 does not validate the checksum of incoming packets.
     testpmd [options] -- --mbuf-size=<your-max-packet-size>
 
 #.  Qemu e1000 does not validate the checksum of incoming packets.

+
+#.  Qemu e1000 only supports one interrupt source, so link and Rx interrupt should be exclusive.
+
+#.  Qemu e1000 does not support interrupt auto-clear, application should disable interrupt immediately when woken up.