[PATCH 5/8] tty: n_gsm: replace dead code with a meaningful comment

[Andrej Krpic <ak77@tnode.com>]

UI/UIH frame can be received as a command from other station or
as a response to a command we issued earlier.

Add this knowledge to the source code as a comment and remove
useless #if 0/#endif block.

Signed-off-by: Andrej Krpic <ak77@tnode.com>
---
 drivers/tty/n_gsm.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 8551fa4..3c4c521 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -1852,10 +1852,11 @@ static void gsm_queue(struct gsm_mux *gsm)
 	case UI|PF:
 	case UIH:
 	case UIH|PF:
-#if 0
-		if (cr)
-			goto invalid;
-#endif
+		/* Don't reject frames based on cr value as UI/UIH
+		 * frame can be received as a command from other
+		 * station or as a response to a command we issued
+		 * earlier.
+		 */
 		if (dlci == NULL || dlci->state != DLCI_OPEN) {
 			gsm_response(gsm, address, DM|PF);
 			return;
-- 
2.7.0