regmap: debugfs: Ensure a correct return value for empty caches

broonie · broonie · commit 5bd9f4bb34c1 · 2013-01-08T20:52:49.000Z
This should never happen in the real world.

Signed-off-by: Mark Brown &lt;broonie@opensource.wolfsonmicro.com&gt;
diff --git a/drivers/base/regmap/regmap-debugfs.c b/drivers/base/regmap/regmap-debugfs.c
@@ -116,6 +116,16 @@ static unsigned int regmap_debugfs_get_dump_start(struct regmap *map,
 		}
 	}
 
+	/*
+	 * This should never happen; we return above if we fail to
+	 * allocate and we should never be in this code if there are
+	 * no registers at all.
+	 */
+	if (list_empty(&map->debugfs_off_cache)) {
+		WARN_ON(list_empty(&map->debugfs_off_cache));
+		return base;
+	}
+
 	/* Find the relevant block */
 	list_for_each_entry(c, &map->debugfs_off_cache, list) {
 		if (from >= c->min && from <= c->max) {
