1 files changed, 12 insertions, 1 deletions

diff --git a/drivers/gpu/drm/i915/intel_dvo.c b/drivers/gpu/drm/i915/intel_dvo.c
index ee328ce8e9fe..2c0be924e9a9 100644
--- a/drivers/gpu/drm/i915/intel_dvo.c
+++ b/drivers/gpu/drm/i915/intel_dvo.c
@@ -455,6 +455,7 @@ void intel_dvo_init(struct drm_device *dev)
                 const struct intel_dvo_device *dvo = &intel_dvo_devices[i];
                 struct i2c_adapter *i2c;
                 int gpio;
+                bool dvoinit;
 
                 /* Allow the I2C driver info to specify the GPIO to be used in
                  * special cases, but otherwise default to what's defined
@@ -474,7 +475,17 @@ void intel_dvo_init(struct drm_device *dev)
                 i2c = intel_gmbus_get_adapter(dev_priv, gpio);
 
                 intel_dvo->dev = *dvo;
-                if (!dvo->dev_ops->init(&intel_dvo->dev, i2c))
+
+                /* GMBUS NAK handling seems to be unstable, hence let the
+                 * transmitter detection run in bit banging mode for now.
+                 */
+                intel_gmbus_force_bit(i2c, true);
+
+                dvoinit = dvo->dev_ops->init(&intel_dvo->dev, i2c);
+
+                intel_gmbus_force_bit(i2c, false);
+
+                if (!dvoinit)
                         continue;
 
                 intel_encoder->type = INTEL_OUTPUT_DVO;