linux-kernel - [PATCH] i2c: fix bit algorithm timeout for low values.

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Date:	Fri, 24 Apr 2009 09:09:13 +1000
From:	Dave Airlie <airlied@...il.com>
To:	linux-i2c@...r.kernel.org, Jean Delvare <khali@...ux-fr.org>
Cc:	linux-kernel@...r.kernel.org, stable@...nel.org,
	Dave Airlie <airlied@...hat.com>
Subject: [PATCH] i2c: fix bit algorithm timeout for low values.

From: Dave Airlie <airlied@...hat.com>

When fetching DDC using i2c algo bit, we were often seeing timeouts
before getting valid EDID on a retry. The VESA spec states 2ms is the
DDC timeout, so when this translates into 1 jiffie and we are close
to the end of the time period, it could return with a timeout less than
2ms.

Change this code to use time_after instead of time_after_eq.

Signed-off-by: Dave Airlie <airlied@...hat.com>
---
 drivers/i2c/algos/i2c-algo-bit.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/i2c/algos/i2c-algo-bit.c b/drivers/i2c/algos/i2c-algo-bit.c
index d420cc5..e25e139 100644
--- a/drivers/i2c/algos/i2c-algo-bit.c
+++ b/drivers/i2c/algos/i2c-algo-bit.c
@@ -104,7 +104,7 @@ static int sclhi(struct i2c_algo_bit_data *adap)
 		 * chips may hold it low ("clock stretching") while they
 		 * are processing data internally.
 		 */
-		if (time_after_eq(jiffies, start + adap->timeout))
+		if (time_after(jiffies, start + adap->timeout))
 			return -ETIMEDOUT;
 		cond_resched();
 	}
-- 
1.6.0.6

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