[PATCH] ipmi: bt restart reset fixes

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@dell.com>
Acked-by: Rocky Craig <rocky.craig@hp.com>
Signed-off-by: Corey Minyard <minyard@acm.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/drivers/char/ipmi/ipmi_bt_sm.c b/drivers/char/ipmi/ipmi_bt_sm.c
index 7c4a195dfc9a415b7f6d5b77988b07555c7846fc..58dcdee1cd719ab3d165907fb76f53c6e55c5db6 100644 (file)
--- a/drivers/char/ipmi/ipmi_bt_sm.c
+++ b/drivers/char/ipmi/ipmi_bt_sm.c
@@ -333,8 +333,7 @@ static void error_recovery(struct si_sm_data *bt, char *reason)
                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 @@ static enum si_sm_result bt_event(struct si_sm_data *bt, long time)
                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;