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

From: Jiri Slaby
Date: Tue Aug 18 2020 - 04:24:29 EST


On 17. 08. 20, 15:54, Tony Lindgren wrote:
> 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.

When exactly does the only writer (gsmld_output) return zero for
non-zero len parameter?

> 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;
>

thanks,
--
js