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* [PATCH] spi/pl022: use cpu_relax in the busy loop
@ 2011-05-19 18:01 Linus Walleij
  2011-05-19 18:03 ` Grant Likely
  0 siblings, 1 reply; 2+ messages in thread
From: Linus Walleij @ 2011-05-19 18:01 UTC (permalink / raw)
  To: Grant Likely, spi-devel-general
  Cc: Linus Walleij, Lee Jones, Linus Walleij, linux-arm-kernel

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>
---
 drivers/spi/amba-pl022.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/drivers/spi/amba-pl022.c b/drivers/spi/amba-pl022.c
index 18667de..8a2b88a 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 */
-- 
1.7.3.2

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2011-05-19 18:01 [PATCH] spi/pl022: use cpu_relax in the busy loop Linus Walleij
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