[PATCH] n_gsm: Fix write handling for zero bytes written

[Tony Lindgren]

If write returns zero we currently end up removing the message
from the queue. Instead of removing the message, we want to just
break out of the loop just like we already do for error codes.

Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
---
 drivers/tty/n_gsm.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -691,7 +691,8 @@ static void gsm_data_kick(struct gsm_mux *gsm, struct gsm_dlci *dlci)
 			print_hex_dump_bytes("gsm_data_kick: ",
 					     DUMP_PREFIX_OFFSET,
 					     gsm->txframe, len);
-		if (gsm->output(gsm, gsm->txframe, len) < 0)
+
+		if (gsm->output(gsm, gsm->txframe, len) <= 0)
 			break;
 		/* FIXME: Can eliminate one SOF in many more cases */
 		gsm->tx_bytes -= msg->len;
-- 
2.28.0