[SCSI] qla2xxx: Correct excessive delay during LOAD-RISC-RAM mailbox …

…command.

Problem report (against 2.4.x driver) from Jeff Layton
<jlayton@redhat.com>:

An OEM noticed that the U6 qla2200 driver would hang for
around 2 minutes at boot time and then proceed normally. I
found that the delay was occurring when loading the new
firmware into the card, and was due to a
schedule_timeout(10) added to the bottom of the polling
loop.

Some testing showed that the load ram operation on the card
was very quick (on the order of a couple of jiffies), but
the sleep in the polling loop was making each operation take
around 25-30.

The attached patch corrects this by making it skip sleeping
during the load ram operation, since I believe we only do
that when the module is plugged in. It also skips sleeping
if the mbox_int flag got set during the current loop.

This corrected the hang on my test setup, and OEM also
confirmed that it corrected the problem for them.

Signed-off-by: Andrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

drivers/scsi/qla2xxx/qla_mbx.c

@@ -196,7 +196,9 @@ qla2x00_mailbox_command(scsi_qla_host_t *ha, mbx_cmd_t *mcp)
 			/* Check for pending interrupts. */
 			qla2x00_poll(ha);
 
-			msleep(10);
+			if (command != MBC_LOAD_RISC_RAM_EXTENDED &&
+			    !ha->flags.mbox_int)
+				msleep(10);
 		} /* while */
 	}