drm/i915: ensure i2c adapter is all set before adding it

i2c_add_adapter() may do i2c transfers on the bus to detect supported devices. Therefore the adapter needs to be all set before adding it. This was not the case for the bit-banging fallback, resulting in an oops if the device detection GMBUS transfers timed out. Fix the issue by calling i2c_add_adapter() only after intel_gpio_setup(). LKML-Reference: <[email protected]> Tested-by: Mihai Moldovan <[email protected]> Signed-off-by: Jani Nikula <[email protected]> Signed-off-by: Daniel Vetter <[email protected]>
mrcsosa · Aug 13, 2012 · cee2516 · cee2516
1 parent 4344b81
commit cee2516
Showing 1 changed file with 4 additions and 3 deletions.
diff --git a/drivers/gpu/drm/i915/intel_i2c.c b/drivers/gpu/drm/i915/intel_i2c.c
@@ -486,9 +486,6 @@ int intel_setup_gmbus(struct drm_device *dev)
 		bus->dev_priv = dev_priv;
 
 		bus->adapter.algo = &gmbus_algorithm;
-		ret = i2c_add_adapter(&bus->adapter);
-		if (ret)
-			goto err;
 
 		/* By default use a conservative clock rate */
 		bus->reg0 = port | GMBUS_RATE_100KHZ;
@@ -498,6 +495,10 @@ int intel_setup_gmbus(struct drm_device *dev)
 			bus->force_bit = true;
 
 		intel_gpio_setup(bus, port);
+
+		ret = i2c_add_adapter(&bus->adapter);
+		if (ret)
+			goto err;
 	}
 
 	intel_i2c_reset(dev_priv->dev);