drm/tegra: Don't disable unused planes
When a plane isn't in use it isn't attached to a CRTC and therefore the
DC registers aren't available for programming.
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
diff --git a/drivers/gpu/host1x/drm/dc.c b/drivers/gpu/host1x/drm/dc.c
index 8c04943..98f60d8 100644
--- a/drivers/gpu/host1x/drm/dc.c
+++ b/drivers/gpu/host1x/drm/dc.c
@@ -79,6 +79,9 @@
struct tegra_plane *p = to_tegra_plane(plane);
unsigned long value;
+ if (!plane->crtc)
+ return 0;
+
value = WINDOW_A_SELECT << p->index;
tegra_dc_writel(dc, value, DC_CMD_DISPLAY_WINDOW_HEADER);