android/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

tty: n_gsm: fix wrong T1 retry count handling

Browse Source 
[ Upstream commit f30e10caa80aa1f35508bc17fc302dbbde9a833c ]

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: e1eaea46bb ("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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Daniel Starke 2022-07-07 13:32:20 +02:00 committed by Greg Kroah-Hartman
parent b16d653bc7
commit 6737d4f5f5
1 changed files with 2 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
drivers/tty/n_gsm.c
View File

@ -1550,8 +1550,8 @@ static void gsm_dlci_t1(struct timer_list *t)
switch (dlci->state) { switch (dlci->state) {
case DLCI_OPENING: case DLCI_OPENING:
dlci->retries--;
if (dlci->retries) { if (dlci->retries) {
dlci->retries--;
gsm_command(dlci->gsm, dlci->addr, SABM|PF); gsm_command(dlci->gsm, dlci->addr, SABM|PF);
mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100); mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100);
} else if (!dlci->addr && gsm->control == (DM | PF)) { } else if (!dlci->addr && gsm->control == (DM | PF)) {
@ -1566,8 +1566,8 @@ static void gsm_dlci_t1(struct timer_list *t)
break; break;
case DLCI_CLOSING: case DLCI_CLOSING:
dlci->retries--;
if (dlci->retries) { if (dlci->retries) {
dlci->retries--;
gsm_command(dlci->gsm, dlci->addr, DISC|PF); gsm_command(dlci->gsm, dlci->addr, DISC|PF);
mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100); mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100);
} else } else