drm/kms: allocate framebuffer cmap

Without an allocated colormap, FBIOGETCMAP fails.  This would make
programs restore an all-black colormap ("links -g") or fail to work
altogether ("mplayer -vo fbdev2").

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 7 insertions, 1 deletions

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index e812babe212..515b838006d 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -908,8 +908,13 @@ int drm_fb_helper_single_fb_probe(struct drm_device *dev,
 
         if (new_fb) {
                 info->var.pixclock = 0;
-                if (register_framebuffer(info) < 0)
+                ret = fb_alloc_cmap(&info->cmap, crtc->gamma_size, 0);
+                if (ret)
+                        return ret;
+                if (register_framebuffer(info) < 0) {
+                        fb_dealloc_cmap(&info->cmap);
                         return -EINVAL;
+                }
         } else {
                 drm_fb_helper_set_par(info);
         }
@@ -939,6 +944,7 @@ void drm_fb_helper_free(struct drm_fb_helper *helper)
                 unregister_sysrq_key('v', &sysrq_drm_fb_helper_restore_op);
         }
         drm_fb_helper_crtc_free(helper);
+        fb_dealloc_cmap(&helper->fb->fbdev->cmap);
 }
 EXPORT_SYMBOL(drm_fb_helper_free);