The VESA specification suggests a 2.2 ms timeout on DDC channels. Only the intel DRM driver implements this properly today, align all drivers to the proper implementation.

Signed-off-by: Jean Delvare jdelvare@suse.de Cc: Eugeni Dodonov eugeni@dodonov.net Cc: Dave Airlie airlied@gmail.com Cc: Keith Packard keithp@keithp.com Cc: Alex Deucher alexdeucher@gmail.com --- drivers/gpu/drm/i915/intel_i2c.c | 2 +- drivers/gpu/drm/nouveau/nouveau_i2c.c | 2 +- drivers/gpu/drm/radeon/radeon_i2c.c | 4 +--- 3 files changed, 3 insertions(+), 5 deletions(-)

--- linux-3.1-rc10.orig/drivers/gpu/drm/i915/intel_i2c.c 2011-10-20 14:59:11.000000000 +0200 +++ linux-3.1-rc10/drivers/gpu/drm/i915/intel_i2c.c 2011-10-20 15:24:33.000000000 +0200 @@ -183,7 +183,7 @@ intel_gpio_create(struct drm_i915_privat gpio->algo.getsda = get_data; gpio->algo.getscl = get_clock; gpio->algo.udelay = I2C_RISEFALL_TIME; - gpio->algo.timeout = usecs_to_jiffies(2200); + gpio->algo.timeout = usecs_to_jiffies(2200); /* from VESA */ gpio->algo.data = gpio;

if (i2c_bit_add_bus(&gpio->adapter)) --- linux-3.1-rc10.orig/drivers/gpu/drm/nouveau/nouveau_i2c.c 2011-10-20 15:14:36.000000000 +0200 +++ linux-3.1-rc10/drivers/gpu/drm/nouveau/nouveau_i2c.c 2011-10-20 15:24:37.000000000 +0200 @@ -218,7 +218,7 @@ nouveau_i2c_init(struct drm_device *dev, if (entry->port_type < 6) { i2c->adapter.algo_data = &i2c->bit; i2c->bit.udelay = 10; - i2c->bit.timeout = usecs_to_jiffies(5000); + i2c->bit.timeout = usecs_to_jiffies(2200); /* from VESA */ i2c->bit.data = i2c; ret = i2c_bit_add_bus(&i2c->adapter); } else { --- linux-3.1-rc10.orig/drivers/gpu/drm/radeon/radeon_i2c.c 2011-10-20 14:58:17.000000000 +0200 +++ linux-3.1-rc10/drivers/gpu/drm/radeon/radeon_i2c.c 2011-10-20 15:24:41.000000000 +0200 @@ -929,9 +929,7 @@ 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) {