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);