[Skiboot] [PATCH] libflash/mbox-flash: only wait for MBOX_DEFAULT_POLL_MS if busy

[Stewart Smith]

This makes the mbox unit test run 300x quicker and seems to
shave about 6 seconds from boot time on Witherspoon.

Signed-off-by: Stewart Smith <stewart at linux.vnet.ibm.com>
---
 libflash/mbox-flash.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/libflash/mbox-flash.c b/libflash/mbox-flash.c
index e15fecf033fb..d33a52c0ebf0 100644
--- a/libflash/mbox-flash.c
+++ b/libflash/mbox-flash.c
@@ -348,8 +348,9 @@ static int wait_for_bmc(struct mbox_flash_data *mbox_flash, unsigned int timeout
 		 * Both functions are important.
 		 * Well time_wait_ms() relaxes the spin... so... its nice
 		 */
-		time_wait_ms(MBOX_DEFAULT_POLL_MS);
 		check_timers(false);
+		if (mbox_flash->busy)
+			time_wait_ms(MBOX_DEFAULT_POLL_MS);
 		asm volatile ("" ::: "memory");
 	}
 
-- 
2.14.3