Input: rc-keymap - return KEY_RESERVED for unknown mappings

Do not respond with -EINVAL to EVIOCGKEYCODE for not-yet-mapped
scancodes, but rather return KEY_RESERVED.

This fixes breakage with Ubuntu's input-kbd utility that stopped
returning full keymaps for remote controls.

Tested-by: Mauro Carvalho Chehab <[e-mail]>
Tested-by: Mark Lord <[e-mail]>
Signed-off-by: Dmitry Torokhov <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

drivers/media/rc/rc-main.c

···
 		index = ir_lookup_by_scancode(rc_map, scancode);
 	}
 
-	if (index >= rc_map->len) {
-		if (!(ke->flags & INPUT_KEYMAP_BY_INDEX))
-			IR_dprintk(1, "unknown key for scancode 0x%04x\n",
-				   scancode);
+	if (index < rc_map->len) {
+		entry = &rc_map->scan[index];
+
+		ke->index = index;
+		ke->keycode = entry->keycode;
+		ke->len = sizeof(entry->scancode);
+		memcpy(ke->scancode, &entry->scancode, sizeof(entry->scancode));
+
+	} else if (!(ke->flags & INPUT_KEYMAP_BY_INDEX)) {
+		/*
+		 * We do not really know the valid range of scancodes
+		 * so let's respond with KEY_RESERVED to anything we
+		 * do not have mapping for [yet].
+		 */
+		ke->index = index;
+		ke->keycode = KEY_RESERVED;
+	} else {
 		retval = -EINVAL;
 		goto out;
 	}
-
-	entry = &rc_map->scan[index];
-
-	ke->index = index;
-	ke->keycode = entry->keycode;
-	ke->len = sizeof(entry->scancode);
-	memcpy(ke->scancode, &entry->scancode, sizeof(entry->scancode));
 
 	retval = 0;