linux-kernel - [PATCH 07/12] viafb: reduce I2C timeout and delay

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Date:	Sun, 19 Sep 2010 07:33:48 +0000
From:	Florian Tobias Schandinat <FlorianSchandinat@....de>
To:	linux-fbdev@...r.kernel.org
Cc:	linux-kernel@...r.kernel.org,
	Florian Tobias Schandinat <FlorianSchandinat@....de>,
	Joseph Chan <JosephChan@....com.tw>,
	Jonathan Corbet <corbet@....net>
Subject: [PATCH 07/12] viafb: reduce I2C timeout and delay

viafb: reduce I2C timeout and delay

This patch reduces the value for I2C timeout and udelay.
The udelay was reduced to 10 (old: 40) which is still very high as for
standard-mode I2C even 5 should work. This gives a speedup of factor 4
when talking to I2C devices.
The timeout was reduced to 2 (old: 20) which is taken from the radeon
driver so it should work as well. This gives a speedup of factor 10 when
detecting that there is no I2C device we want to talk to.
This causes a huge improvement of device initialization time.

Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@....de>
Cc: Joseph Chan <JosephChan@....com.tw>
Cc: Jonathan Corbet <corbet@....net>
---
 drivers/video/via/via_i2c.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/video/via/via_i2c.c b/drivers/video/via/via_i2c.c
index 021112e..3844b55 100644
--- a/drivers/video/via/via_i2c.c
+++ b/drivers/video/via/via_i2c.c
@@ -202,8 +202,8 @@ static int create_i2c_bus(struct i2c_adapter *adapter,
 	algo->setscl = via_i2c_setscl;
 	algo->getsda = via_i2c_getsda;
 	algo->getscl = via_i2c_getscl;
-	algo->udelay = 40;
-	algo->timeout = 20;
+	algo->udelay = 10;
+	algo->timeout = 2;
 	algo->data = adap_cfg;
 
 	sprintf(adapter->name, "viafb i2c io_port idx 0x%02x",
-- 
1.6.3.2

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