Index: uspace/srv/hid/display/cursor.c
===================================================================
--- uspace/srv/hid/display/cursor.c	(revision a65b0c8457bb1f713a9496fcda0af8799f5a3dd6)
+++ uspace/srv/hid/display/cursor.c	(revision 84e74ea2e2ddd81f8b1078cf08c150b4e01f0ad3)
@@ -103,5 +103,5 @@
 	errno_t rc;
 
-	dgc = ds_display_get_gc(cursor->display); // XXX
+	dgc = ds_display_get_gc(cursor->display);
 	if (dgc == NULL)
 		return EOK;
Index: uspace/srv/hid/display/display.c
===================================================================
--- uspace/srv/hid/display/display.c	(revision a65b0c8457bb1f713a9496fcda0af8799f5a3dd6)
+++ uspace/srv/hid/display/display.c	(revision 84e74ea2e2ddd81f8b1078cf08c150b4e01f0ad3)
@@ -585,9 +585,21 @@
 }
 
-// XXX
+/** Get unbuffered GC.
+ *
+ * Get the display's (unbuffered) graphic context. If the display
+ * is double-buffered, this returns GC of the front buffer. If the display
+ * is unbuffered, this is the same as @c ds_display_get_gc().
+ *
+ * @param display Display
+ * @return Unbuffered GC
+ */
 static gfx_context_t *ds_display_get_unbuf_gc(ds_display_t *display)
 {
 	ds_ddev_t *ddev;
 
+	/*
+	 * XXX To properly support multiple display devices, create
+	 * a cloning GC that copies rendering operation to each output.
+	 */
 	ddev = ds_display_first_ddev(display);
 	if (ddev == NULL)
@@ -597,5 +609,12 @@
 }
 
-// XXX
+/** Get display GC.
+ *
+ * Get the graphic context used to paint the display. This is to be used
+ * for all display server paint operations.
+ *
+ * @param display Display
+ * @return Graphic context for painting to the display
+ */
 gfx_context_t *ds_display_get_gc(ds_display_t *display)
 {
@@ -622,5 +641,5 @@
 		crect = disp->rect;
 
-	gc = ds_display_get_gc(disp); // XXX
+	gc = ds_display_get_gc(disp);
 	if (gc == NULL)
 		return EOK;
Index: uspace/srv/hid/display/window.c
===================================================================
--- uspace/srv/hid/display/window.c	(revision a65b0c8457bb1f713a9496fcda0af8799f5a3dd6)
+++ uspace/srv/hid/display/window.c	(revision 84e74ea2e2ddd81f8b1078cf08c150b4e01f0ad3)
@@ -84,5 +84,5 @@
 	bparams.rect = params->rect;
 
-	dgc = ds_display_get_gc(wnd->display); // XXX
+	dgc = ds_display_get_gc(wnd->display);
 	if (dgc != NULL) {
 		rc = gfx_bitmap_create(dgc, &bparams, NULL, &wnd->bitmap);
@@ -268,5 +268,5 @@
 		return rc;
 
-	gc = ds_display_get_gc(wnd->display); // XXX
+	gc = ds_display_get_gc(wnd->display);
 	if (gc != NULL) {
 		gfx_set_color(gc, color);
@@ -695,5 +695,5 @@
 	errno_t rc;
 
-	dgc = ds_display_get_gc(wnd->display); // XXX
+	dgc = ds_display_get_gc(wnd->display);
 	if (dgc != NULL) {
 		gfx_bitmap_params_init(&bparams);