diff options
| author |   Daniel Starke <daniel.starke@siemens.com> | 2022-07-07 13:32:20 +0200 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-07-08 15:14:53 +0200 |
| commit | f30e10caa80aa1f35508bc17fc302dbbde9a833c (patch) | |
| tree | a8fcb1fcb3c6c2a99c34aaf32d9fb6a82f454533 /drivers/tty | |
| parent | serial: RS485 termination is supported if DT provides one (diff) | |
| download | linux-dev-f30e10caa80aa1f35508bc17fc302dbbde9a833c.tar.xz linux-dev-f30e10caa80aa1f35508bc17fc302dbbde9a833c.zip | |
tty: n_gsm: fix wrong T1 retry count handling
n_gsm is based on the 3GPP 07.010 and its newer version is the 3GPP 27.010.
See https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=1516
The changes from 07.010 to 27.010 are non-functional. Therefore, I refer to
the newer 27.010 here. Chapter 5.7.3 states that the valid range for the
maximum number of retransmissions (N2) is from 0 to 255 (both including).
gsm_dlci_t1() handles this number incorrectly by performing N2 - 1
retransmission attempts. Setting N2 to zero results in more than 255
retransmission attempts.
Fix gsm_dlci_t1() to comply with 3GPP 27.010.
Fixes: e1eaea46bb40 ("tty: n_gsm line discipline")
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220707113223.3685-1-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 | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c index ba399a660573..1a70e7ae90cc 100644 --- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -1805,8 +1805,8 @@ static void gsm_dlci_t1(struct timer_list *t) switch (dlci->state) { case DLCI_OPENING: - dlci->retries--; if (dlci->retries) { + dlci->retries--; gsm_command(dlci->gsm, dlci->addr, SABM|PF); mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100); } else if (!dlci->addr && gsm->control == (DM | PF)) { @@ -1821,8 +1821,8 @@ static void gsm_dlci_t1(struct timer_list *t) break; case DLCI_CLOSING: - dlci->retries--; if (dlci->retries) { + dlci->retries--; gsm_command(dlci->gsm, dlci->addr, DISC|PF); mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100); } else |