[Skiboot] [PATCH v2] bt: use the maximum retry count returned by the BMC

[Cédric Le Goater]

OpenPower systems using a AMI firmware on the BMC have a BT device
configured with a capability of '1' maximum retry. The following code
is equivalent to what skiboot currently supports but it will now also
handle setups of other BT devices, like in qemu or OpenBMC.

Signed-off-by: Cédric Le Goater <clg at fr.ibm.com>
---

 Changes since v2:

 - rename send_count to retries. Suggested by Vipin.

 hw/bt.c |   12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

Index: skiboot.git/hw/bt.c
===================================================================
--- skiboot.git.orig/hw/bt.c
+++ skiboot.git/hw/bt.c
@@ -74,7 +74,7 @@
 /*
  * Maximum number of times to attempt sending a message before giving up.
  */
-#define BT_MAX_SEND_COUNT 2
+#define BT_MAX_RETRIES 1
 
 #define BT_QUEUE_DEBUG 0
 
@@ -112,7 +112,7 @@ struct bt_caps {
 	uint16_t input_buf_len;
 	uint16_t output_buf_len;
 	uint8_t msg_timeout;
-	uint8_t num_retries;
+	uint8_t max_retries;
 };
 
 struct bt {
@@ -183,13 +183,13 @@ static void get_bt_caps_complete(struct
 	bt.caps.input_buf_len = msg->data[1] + 1;
 	bt.caps.output_buf_len = msg->data[2] + 1;
 	bt.caps.msg_timeout = msg->data[3];
-	bt.caps.num_retries = msg->data[4];
+	bt.caps.max_retries = msg->data[4];
 	prlog(PR_DEBUG, "BMC BT capabilities received:\n");
 	prlog(PR_DEBUG, "buffer sizes: %d input %d output\n",
 			bt.caps.input_buf_len, bt.caps.output_buf_len);
 	prlog(PR_DEBUG, "number of requests: %d\n", bt.caps.num_requests);
 	prlog(PR_DEBUG,  "msg timeout: %d max retries: %d\n",
-			bt.caps.msg_timeout, bt.caps.num_retries);
+			bt.caps.msg_timeout, bt.caps.max_retries);
 
 out:
 	ipmi_free_msg(msg);
@@ -392,7 +392,7 @@ static void bt_expire_old_msg(uint64_t t
 
 	if (bt_msg && bt_msg->tb > 0 &&
 	    (tb_compare(tb, bt_msg->tb + secs_to_tb(bt.caps.msg_timeout)) == TB_AAFTERB)) {
-		if (bt_msg->send_count < BT_MAX_SEND_COUNT) {
+		if (bt_msg->send_count <= bt.caps.max_retries) {
 			/* A message timeout is usually due to the BMC
 			clearing the H2B_ATN flag without actually
 			doing anything. The data will still be in the
@@ -629,7 +629,7 @@ void bt_init(void)
 	bt.caps.input_buf_len = BT_FIFO_LEN;
 	bt.caps.output_buf_len = BT_FIFO_LEN;
 	bt.caps.msg_timeout = BT_MSG_TIMEOUT;
-	bt.caps.num_retries = 1;
+	bt.caps.max_retries = BT_MAX_RETRIES;
 
 	/* We support only one */
 	n = dt_find_compatible_node(dt_root, NULL, "ipmi-bt");