diff options
| author | Daniel Starke <daniel.starke@siemens.com> | 2022-11-03 10:17:41 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-11-09 13:03:58 +0100 |
| commit | 7a1212475f5e313c11300272f34ffa32462bbeef (patch) | |
| tree | 6ca7101753e660640d510b72b31629a993ae2de0 /drivers/tty | |
| parent | serial: 8250: 8250_omap: Fix calculation of RS485 delays (diff) | |
| download | linux-7a1212475f5e313c11300272f34ffa32462bbeef.tar.xz linux-7a1212475f5e313c11300272f34ffa32462bbeef.zip | |
tty: n_gsm: introduce macro for minimal unit size
n_gsm has a minimal protocol overhead of 7 bytes. The current code already
checks whether the configured MRU/MTU size is at least one byte more than
this.
Introduce the macro MIN_MTU to make this value more obvious.
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20221103091743.2119-1-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/n_gsm.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c index 5e516f5cac5a..570c40a3d78f 100644 --- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -89,6 +89,7 @@ module_param(debug, int, 0600); */ #define MAX_MRU 1500 #define MAX_MTU 1500 +#define MIN_MTU (PROT_OVERHEAD + 1) /* SOF, ADDR, CTRL, LEN1, LEN2, ..., FCS, EOF */ #define PROT_OVERHEAD 7 #define GSM_NET_TX_TIMEOUT (HZ*10) @@ -2712,7 +2713,9 @@ static int gsm_config(struct gsm_mux *gsm, struct gsm_config *c) if ((c->adaption != 1 && c->adaption != 2) || c->k) return -EOPNOTSUPP; /* Check the MRU/MTU range looks sane */ - if (c->mru > MAX_MRU || c->mtu > MAX_MTU || c->mru < 8 || c->mtu < 8) + if (c->mru < MIN_MTU || c->mtu < MIN_MTU) + return -EINVAL; + if (c->mru > MAX_MRU || c->mtu > MAX_MTU) return -EINVAL; if (c->n2 > 255) return -EINVAL; @@ -3296,7 +3299,7 @@ static int gsm_create_network(struct gsm_dlci *dlci, struct gsm_netconfig *nc) return -ENOMEM; } net->mtu = dlci->gsm->mtu; - net->min_mtu = 8; + net->min_mtu = MIN_MTU; net->max_mtu = dlci->gsm->mtu; mux_net = netdev_priv(net); mux_net->dlci = dlci; |