From: Linus Walleij <linus.walleij@stericsson.com>
Date: Thu, 19 May 2011 18:01:25 +0000 (+0200)
Subject: spi/pl022: use cpu_relax in the busy loop
X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=521999bd4a8c47a86136b9d8223a9480f5906db8;p=deliverable%2Flinux.git

spi/pl022: use cpu_relax in the busy loop

This relaxes the cpu in the polling busy-wait loop.

Reported-by: Vitaly Wool <vitalywool@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
---

diff --git a/drivers/spi/amba-pl022.c b/drivers/spi/amba-pl022.c
index 18667de436f1..8a2b88aee373 100644
--- a/drivers/spi/amba-pl022.c
+++ b/drivers/spi/amba-pl022.c
@@ -1424,6 +1424,7 @@ static void do_polling_transfer(struct pl022 *pl022)
 				message->state = STATE_ERROR;
 				goto out;
 			}
+			cpu_relax();
 		}
 
 		/* Update total byte transferred */