net: hsr: add support for EntryForgetTime

In IEC 62439-3 EntryForgetTime is defined with a value of 400 ms. When a
node does not send any frame within this time, the sequence number check
for can be ignored. This solves communication issues with Cisco IE 2000
in Redbox mode.

Fixes: f421436a591d ("net/hsr: Add support for the High-availability Seamless Redundancy protocol (HSRv0)")
Signed-off-by: Marco Wenzel <marco.wenzel@a-eberle.de>
Reviewed-by: George McCollister <george.mccollister@gmail.com>
Tested-by: George McCollister <george.mccollister@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20210224094653.1440-1-marco.wenzel@a-eberle.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
diff --git a/net/hsr/hsr_framereg.c b/net/hsr/hsr_framereg.c
index f9a8cc8..bb1351c 100644
--- a/net/hsr/hsr_framereg.c
+++ b/net/hsr/hsr_framereg.c
@@ -164,8 +164,10 @@ static struct hsr_node *hsr_add_node(struct hsr_priv *hsr,
 	 * as initialization. (0 could trigger an spurious ring error warning).
 	 */
 	now = jiffies;
-	for (i = 0; i < HSR_PT_PORTS; i++)
+	for (i = 0; i < HSR_PT_PORTS; i++) {
 		new_node->time_in[i] = now;
+		new_node->time_out[i] = now;
+	}
 	for (i = 0; i < HSR_PT_PORTS; i++)
 		new_node->seq_out[i] = seq_out;
 
@@ -413,9 +415,12 @@ void hsr_register_frame_in(struct hsr_node *node, struct hsr_port *port,
 int hsr_register_frame_out(struct hsr_port *port, struct hsr_node *node,
 			   u16 sequence_nr)
 {
-	if (seq_nr_before_or_eq(sequence_nr, node->seq_out[port->type]))
+	if (seq_nr_before_or_eq(sequence_nr, node->seq_out[port->type]) &&
+	    time_is_after_jiffies(node->time_out[port->type] +
+	    msecs_to_jiffies(HSR_ENTRY_FORGET_TIME)))
 		return 1;
 
+	node->time_out[port->type] = jiffies;
 	node->seq_out[port->type] = sequence_nr;
 	return 0;
 }