drm/tegra: fb: Properly support linear modifier

Instead of relying on the tiling attached to a buffer object, make sure
to set the proper tiling for linear buffers.

Signed-off-by: Thierry Reding <treding@nvidia.com>

drivers/gpu/drm/tegra/fb.c

@@ -55,6 +55,11 @@ int tegra_fb_get_tiling(struct drm_framebuffer *framebuffer,
 	uint64_t modifier = fb->base.modifier;
 
 	switch (modifier) {
+	case DRM_FORMAT_MOD_LINEAR:
+		tiling->mode = TEGRA_BO_TILING_MODE_PITCH;
+		tiling->value = 0;
+		break;
+
 	case DRM_FORMAT_MOD_NVIDIA_TEGRA_TILED:
 		tiling->mode = TEGRA_BO_TILING_MODE_TILED;
 		tiling->value = 0;
@@ -91,9 +96,7 @@ int tegra_fb_get_tiling(struct drm_framebuffer *framebuffer,
 		break;
 
 	default:
-		/* TODO: handle YUV formats? */
-		*tiling = fb->planes[0]->tiling;
-		break;
+		return -EINVAL;
 	}
 
 	return 0;