[PATCH 2/2] drm/radeon/kms: Use the standard VESA timeout for DDC channels

[Jean Delvare <jdelvare@suse.de>]

The VESA specification suggests a 2.2 ms timeout on DDC channels.
Use exactly that (as the i915 driver does) instead of hard-coding a
jiffy count.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Keith Packard <keithp@keithp.com>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Alex Deucher <alexdeucher@gmail.com>
---
Already sent on: 2011-10-21.

 drivers/gpu/drm/radeon/radeon_i2c.c |    4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)
--- linux-3.3-rc1.orig/drivers/gpu/drm/radeon/radeon_i2c.c	2012-01-28 10:37:51.722069517 +0100
+++ linux-3.3-rc1/drivers/gpu/drm/radeon/radeon_i2c.c	2012-01-28 10:39:26.996070929 +0100
@@ -925,9 +925,7 @@ struct radeon_i2c_chan *radeon_i2c_creat
 		i2c->algo.bit.getsda = get_data;
 		i2c->algo.bit.getscl = get_clock;
 		i2c->algo.bit.udelay = 10;
-		/* vesa says 2.2 ms is enough, 1 jiffy doesn't seem to always
-		 * make this, 2 jiffies is a lot more reliable */
-		i2c->algo.bit.timeout = 2;
+		i2c->algo.bit.timeout = usecs_to_jiffies(2200);	/* from VESA */
 		i2c->algo.bit.data = i2c;
 		ret = i2c_bit_add_bus(&i2c->adapter);
 		if (ret) {

-- 
Jean Delvare
Suse L3