Frames may be separated with a single SOF (5.2.6.1 of 27.010 mux spec).
While transmission of a single SOF between frames is implemented in
gsm_data_kick, the reception isn't.
As a side effect, it is now possible to receive and ignore a stream of
consecutive SOFs (5.2.5 of 27.010 mux spec).
Signed-off-by: Andrej Krpic <a...@tnode.com>
---
drivers/tty/n_gsm.c | 18 ++++++++++--------
1 file changed, 10 insertions(+), 8 deletions(-)
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index b0d9edd..12b149d 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -1895,9 +1895,14 @@ static void gsm0_receive(struct gsm_mux *gsm, unsigned
char c)
}
break;
case GSM_ADDRESS: /* Address EA */
- gsm->fcs = gsm_fcs_add(gsm->fcs, c);
+ /* Ignore (not first) GSM0_SOF as it decodes into
+ * reserved DLCI 62 (5.6 of the 27.010 mux spec).
+ */
+ if (c == GSM0_SOF)
+ break;
if (gsm_read_ea(&gsm->address, c))
gsm->state = GSM_CONTROL;
+ gsm->fcs = gsm_fcs_add(gsm->fcs, c);
break;
case GSM_CONTROL: /* Control Byte */
gsm->fcs = gsm_fcs_add(gsm->fcs, c);
@@ -1944,13 +1949,10 @@ static void gsm0_receive(struct gsm_mux *gsm, unsigned
char c)
case GSM_FCS: /* FCS follows the packet */
gsm->received_fcs = c;
gsm_queue(gsm);
- gsm->state = GSM_SSOF;
- break;
- case GSM_SSOF:
- if (c == GSM0_SOF) {
- gsm->state = GSM_SEARCH;
- break;
- }
+ /* Frames can be separated with a single GSM0_SOF.
+ * Deal with consecutive GSM0_SOFs in GSM_ADDRESS.
+ */
+ gsm->state = GSM_SEARCH;
break;
}
}
--
2.7.0
