[PATCH 7/9] ipmi: bt restart reset fixes

[Corey Minyard]

The current BT retry/reset mechanism fails to succeed on a PowerEdge
1650, when the controller is wedged with B2H_ATN asserted at
XACTION_START.  If this occurs, no further commands will ever succeed
unless the state of the controller is first cleared out.

Furthermore, the soft reset would only occur if the first command
after insmod was the one that timed out, not if a later command timed out.

This patch changes the retry/reset mechanism to be as follows:

Before retrying a command, clear the state of the BT controller such
that the flags represent ready for a new transaction.  This increases
the chance of success of the restarted transaction.

After 2 retries, issue a soft reset and retry one more time before
giving up and reporting back a failure.

Signed-off-by: Matt Domsch <Matt_Domsch@xxxxxxxx>
Acked-by: Rocky Craig <rocky.craig@xxxxxx>
Signed-off-by: Corey Minyard <minyard@xxxxxxx>

Index: linux-2.6.ipmi/drivers/char/ipmi/ipmi_bt_sm.c
===================================================================
--- linux-2.6.ipmi.orig/drivers/char/ipmi/ipmi_bt_sm.c	2005-10-10 12:02:10.%N -0500
+++ linux-2.6.ipmi/drivers/char/ipmi/ipmi_bt_sm.c	2005-10-13 14:35:14.%N -0500
@@ -333,8 +333,7 @@
 		bt->state = BT_STATE_HOSED;
 		if (!bt->nonzero_status)
 			printk(KERN_ERR "IPMI: BT stuck, try power cycle\n");
-		else if (bt->seq == FIRST_SEQ + BT_RETRY_LIMIT) {
-			/* most likely during insmod */
+		else if (bt->error_retries <= BT_RETRY_LIMIT + 1) {
 			printk(KERN_DEBUG "IPMI: BT reset (takes 5 secs)\n");
         		bt->state = BT_STATE_RESET1;
 		}
@@ -475,6 +474,7 @@
 		break;
 
 	case BT_STATE_RESTART:		/* don't reset retries! */
+		reset_flags(bt);
 		bt->write_data[2] = ++bt->seq;
 		bt->read_count = 0;
 		bt->nonzero_status = 0;
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/