diff --git a/[refs] b/[refs]
index bfea64700b71..ce17c3842232 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: b872a37437e93df9d112ce674752b3b3a0a17020
+refs/heads/master: 6c47e5c23aa2a7c54ad7ac13af4bd56cd9e703bf
diff --git a/trunk/drivers/gpu/drm/radeon/radeon_atombios.c b/trunk/drivers/gpu/drm/radeon/radeon_atombios.c
index d2d179267af3..0a4ec1ed02c0 100644
--- a/trunk/drivers/gpu/drm/radeon/radeon_atombios.c
+++ b/trunk/drivers/gpu/drm/radeon/radeon_atombios.c
@@ -85,6 +85,18 @@ static struct radeon_i2c_bus_rec radeon_lookup_i2c_gpio(struct radeon_device *rd
 		for (i = 0; i < num_indices; i++) {
 			gpio = &i2c_info->asGPIO_Info[i];
 
+			/* r4xx mask is technically not used by the hw, so patch in the legacy mask bits */
+			if ((rdev->family == CHIP_R420) ||
+			    (rdev->family == CHIP_R423) ||
+			    (rdev->family == CHIP_RV410)) {
+				if ((le16_to_cpu(gpio->usClkMaskRegisterIndex) == 0x0018) ||
+				    (le16_to_cpu(gpio->usClkMaskRegisterIndex) == 0x0019) ||
+				    (le16_to_cpu(gpio->usClkMaskRegisterIndex) == 0x001a)) {
+					gpio->ucClkMaskShift = 0x19;
+					gpio->ucDataMaskShift = 0x18;
+				}
+			}
+
 			/* some evergreen boards have bad data for this entry */
 			if (ASIC_IS_DCE4(rdev)) {
 				if ((i == 7) &&