[Skiboot] [PATCH] hw/bt.c: Timeout messages when bt interface isn't functional

[Alistair Popple]

During system bring up we may not have a properly functioning ipmi
interface. This prevents skiboot completing the boot process as it
waits for certain bt messages to complete before continuing.

This patch alters the bt message timeouts to ensure messages timeout
in the case of a non-responsive bt interface.

Signed-off-by: Alistair Popple <alistair at popple.id.au>
---
 hw/bt.c | 26 +++++++++++++++++---------
 1 file changed, 17 insertions(+), 9 deletions(-)

diff --git a/hw/bt.c b/hw/bt.c
index 41fe24e..7383ce9 100644
--- a/hw/bt.c
+++ b/hw/bt.c
@@ -165,15 +165,11 @@ static void bt_reset_interface(void)
 /* Try and send a message from the message queue. Caller must hold
  * bt.bt_lock and bt.lock and ensue the message queue is not
  * empty. */
-static void bt_send_msg(void)
+static void bt_send_msg(struct bt_msg *bt_msg)
 {
 	int i;
-	struct bt_msg *bt_msg;
 	struct ipmi_msg *ipmi_msg;
 
-	bt_msg = list_top(&bt.msgq, struct bt_msg, link);
-	assert(bt_msg);
-
 	ipmi_msg = &bt_msg->ipmi_msg;
 
 	/* Send the message */
@@ -195,7 +191,6 @@ static void bt_send_msg(void)
 	for (i = 0; i < ipmi_msg->req_size; i++)
 		bt_outb(ipmi_msg->data[i], BT_HOST2BMC);
 
-	bt_msg->tb = mftb();
 	bt_outb(BT_CTRL_H2B_ATN, BT_CTRL);
 	bt_set_state(BT_STATE_RESP_WAIT);
 
@@ -346,9 +341,22 @@ static void print_debug_queue_info(void) {}
 
 static void bt_send_and_unlock(void)
 {
-	if (lpc_ok() && bt_idle() && !list_empty(&bt.msgq)
-	    && bt.state == BT_STATE_IDLE)
-		bt_send_msg();
+	if (lpc_ok() && !list_empty(&bt.msgq)) {
+		struct bt_msg *bt_msg;
+
+		bt_msg = list_top(&bt.msgq, struct bt_msg, link);
+		assert(bt_msg);
+
+		/* Start the message timeout once it gets to the top
+		 * of the queue. This will ensure we timeout messages
+		 * in the case of a broken bt interface as occurs when
+		 * the BMC is not responding to any IPMI messages. */
+		if (bt_msg->tb == 0)
+			bt_msg->tb = mftb();
+
+		if (bt_idle() && bt.state == BT_STATE_IDLE)
+			bt_send_msg(bt_msg);
+	}
 
 	unlock(&bt.lock);
 	return;
-- 
2.1.4