drm/radeon: Extended DDC Probing for ECS A740GM-M DVI-D Connector

ECS A740GM-M with ATI RADEON 2100 sends data to i2c bus
   for a DVI connector that is not implemented/existent on the board.

   Fix by applying extented DDC probing for this connector.

   Requires [PATCH] drm/radeon: Extended DDC Probing for Connectors
   with Improperly Wired DDC Lines

   Tested for kernel 2.6.38 on Asus ECS A740GM-M board

   BugLink: http://bugs.launchpad.net/bugs/810926

Cc: <stable@kernel.org>
Signed-off-by: Thomas Reim <reimth@gmail.com>
Reviewed-by: Alex Deucher <alexdeucher@gmail.com>
Acked-by: Stephen Michaels <Stephen.Micheals@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/radeon/radeon_connectors.c

@@ -455,6 +455,15 @@ static bool radeon_connector_needs_extended_probe(struct radeon_device *dev,
 		    (supported_device == ATOM_DEVICE_DFP2_SUPPORT))
 			return true;
 	}
+	/* ECS A740GM-M with ATI RADEON 2100 sends data to i2c bus
+	 * for a DVI connector that is not implemented */
+	if ((dev->pdev->device == 0x796e) &&
+	    (dev->pdev->subsystem_vendor == 0x1019) &&
+	    (dev->pdev->subsystem_device == 0x2615)) {
+		if ((connector_type == DRM_MODE_CONNECTOR_DVID) &&
+		    (supported_device == ATOM_DEVICE_DFP2_SUPPORT))
+			return true;
+	}
 
 	/* Default: no EDID header probe required for DDC probing */
 	return false;