drm/radeon/kms: properly handle mode id with native mode changes

drm modes are objects with indentifiers.  Make sure to preserve
the mode id when copying mode params.
Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/radeon/radeon_connectors.c

@@ -183,8 +183,7 @@ static struct drm_display_mode *radeon_fp_native_mode(struct drm_encoder *encode
 	if (native_mode->hdisplay != 0 &&
 	    native_mode->vdisplay != 0 &&
 	    native_mode->clock != 0) {
-		mode = drm_mode_create(dev);
-		*mode = *native_mode;
+		mode = drm_mode_duplicate(dev, native_mode);
 		mode->type = DRM_MODE_TYPE_PREFERRED | DRM_MODE_TYPE_DRIVER;
 		drm_mode_set_name(mode);
 

drivers/gpu/drm/radeon/radeon_encoders.c

@@ -175,11 +175,13 @@ void radeon_rmx_mode_fixup(struct drm_encoder *encoder,
 
 	if (mode->hdisplay < native_mode->hdisplay ||
 	    mode->vdisplay < native_mode->vdisplay) {
+		int mode_id = adjusted_mode->base.id;
 		*adjusted_mode = *native_mode;
 		if (!ASIC_IS_AVIVO(rdev)) {
 			adjusted_mode->hdisplay = mode->hdisplay;
 			adjusted_mode->vdisplay = mode->vdisplay;
 		}
+		adjusted_mode->base.id = mode_id;
 	}
 }