1 files changed, 13 insertions, 1 deletions

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index dff205849b34..3d13ca6e257f 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -168,6 +168,9 @@ static void drm_fb_helper_save_lut_atomic(struct drm_crtc *crtc, struct drm_fb_h
         uint16_t *r_base, *g_base, *b_base;
         int i;
 
+        if (helper->funcs->gamma_get == NULL)
+                return;
+
         r_base = crtc->gamma_store;
         g_base = r_base + crtc->gamma_size;
         b_base = g_base + crtc->gamma_size;
@@ -597,6 +600,14 @@ static int setcolreg(struct drm_crtc *crtc, u16 red, u16 green,
                 return 0;
         }
 
+        /*
+         * The driver really shouldn't advertise pseudo/directcolor
+         * visuals if it can't deal with the palette.
+         */
+        if (WARN_ON(!fb_helper->funcs->gamma_set ||
+                    !fb_helper->funcs->gamma_get))
+                return -EINVAL;
+
         pindex = regno;
 
         if (fb->bits_per_pixel == 16) {
@@ -677,7 +688,8 @@ int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info)
                         if (rc)
                                 goto out;
                 }
-                crtc_funcs->load_lut(crtc);
+                if (crtc_funcs->load_lut)
+                        crtc_funcs->load_lut(crtc);
         }
  out:
         drm_modeset_unlock_all(dev);