From: Jim Cromie <jim.cromie@gmail.com>

read_args() fails on '_' (the last opt-char), and returns null.
report this against the opt-char.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 lib/dynamic_debug.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 089765afc972..3d0c6b5faa31 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -903,8 +903,11 @@ static int ddebug_parse_flags(const char *str, struct flag_settings *modifiers)
 				read_args = opt_array[i].read_args;
 				if (read_args) {
 					str = read_args(str, modifiers);
-					if (!str)
+					if (!str) {
+						pr_err("err on '%c'\n",
+						       opt_array[i].opt_char);
 						return -EINVAL;
+					}
 				}
 				break;
 			}
-- 
2.43.0.687.g38aa6559b0-goog