[PATCH 3.2 09/46] ipmi: fix timeout calculation when bmc is disconnected

[Ben Hutchings]

3.2.81-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Xie XiuQi <xiexiuqi@xxxxxxxxxx>

commit e21404dc0ac7ac971c1e36274b48bb460463f4e5 upstream.

Loading ipmi_si module while bmc is disconnected, we found the timeout
is longer than 5 secs.  Actually it takes about 3 mins and 20
secs.(HZ=250)

error message as below:
  Dec 12 19:08:59 linux kernel: IPMI BT: timeout in RD_WAIT [ ] 1 retries left
  Dec 12 19:08:59 linux kernel: BT: write 4 bytes seq=0x01 03 18 00 01
  [...]
  Dec 12 19:12:19 linux kernel: IPMI BT: timeout in RD_WAIT [ ]
  Dec 12 19:12:19 linux kernel: failed 2 retries, sending error response
  Dec 12 19:12:19 linux kernel: IPMI: BT reset (takes 5 secs)
  Dec 12 19:12:19 linux kernel: IPMI BT: flag reset [ ]

Function wait_for_msg_done() use schedule_timeout_uninterruptible(1) to
sleep 1 tick, so we should subtract jiffies_to_usecs(1) instead of 100
usecs from timeout.

Reported-by: Hu Shiyuan <hushiyuan@xxxxxxxxxx>
Signed-off-by: Xie XiuQi <xiexiuqi@xxxxxxxxxx>
Signed-off-by: Corey Minyard <cminyard@xxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
Cc: sebastian.riemer@xxxxxxxxxxxxxxxx
Cc: cminyard@xxxxxxxxxx
Cc: openipmi-developer@xxxxxxxxxxxxxxxxxxxxx
---
 drivers/char/ipmi/ipmi_si_intf.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/char/ipmi/ipmi_si_intf.c
+++ b/drivers/char/ipmi/ipmi_si_intf.c
@@ -2679,7 +2679,7 @@ static int wait_for_msg_done(struct smi_
 		    smi_result == SI_SM_CALL_WITH_TICK_DELAY) {
 			schedule_timeout_uninterruptible(1);
 			smi_result = smi_info->handlers->event(
-				smi_info->si_sm, 100);
+				smi_info->si_sm, jiffies_to_usecs(1));
 		} else if (smi_result == SI_SM_CALL_WITHOUT_DELAY) {
 			smi_result = smi_info->handlers->event(
 				smi_info->si_sm, 0);