From: Tony Lindgren <tony@xxxxxxxxxxx> [ Upstream commit 9136c68346d096697935b9840782f7051d5796c5 ] We currently have gsmld_output() ignore the return value from device write. This means we will lose packets if device write returns 0 or an error. Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx> Link: https://lore.kernel.org/r/20210930060624.46523-1-tony@xxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/tty/n_gsm.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c index 1767503de744..0722860b6f54 100644 --- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -692,7 +692,7 @@ 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 (gsmld_output(gsm, gsm->txframe, len) < 0) + if (gsmld_output(gsm, gsm->txframe, len) <= 0) break; /* FIXME: Can eliminate one SOF in many more cases */ gsm->tx_bytes -= msg->len; @@ -2373,8 +2373,7 @@ static int gsmld_output(struct gsm_mux *gsm, u8 *data, int len) if (debug & 4) print_hex_dump_bytes("gsmld_output: ", DUMP_PREFIX_OFFSET, data, len); - gsm->tty->ops->write(gsm->tty, data, len); - return len; + return gsm->tty->ops->write(gsm->tty, data, len); } /** -- 2.35.1
