lapd_core: fix program flow

when the lapd core is in state LAPD_STATE_SABM_SENT, and the
retransmission counter exceeds (link down) lapd_t200_cb() will
send an RELASE_INDICATION and an MDL_ERROR_INDICATION to L3.
This action is done before the state is processed. This seems
to be no problem with standard retransmission counts (n200),
but may cause timing problems that lead to deadlock states when
custom timer configurations are in use. (Ericsson RBS).

This commit moves the functions calls for sending the indications
mentioned above to the very end of the if branch to relax the
timing again. (See lapd_t200_cb())

Change-Id: I1c1beb3701b19744a3ce9946abca7767d20a0b6a
This commit is contained in:
Philipp Maier 2016-12-08 10:45:06 +01:00
parent b288853ffa
commit d9f6129350
1 changed files with 5 additions and 5 deletions

View File

@ -556,11 +556,6 @@ static void lapd_t200_cb(void *data)
case LAPD_STATE_SABM_SENT:
/* 5.4.1.3 */
if (dl->retrans_ctr + 1 >= dl->n200_est_rel + 1) {
/* send RELEASE INDICATION to L3 */
send_dl_simple(PRIM_DL_REL, PRIM_OP_INDICATION,
&dl->lctx);
/* send MDL ERROR INIDCATION to L3 */
mdl_error(MDL_CAUSE_T200_EXPIRED, &dl->lctx);
/* flush tx and send buffers */
lapd_dl_flush_tx(dl);
lapd_dl_flush_send(dl);
@ -569,6 +564,11 @@ static void lapd_t200_cb(void *data)
/* NOTE: we must not change any other states or buffers
* and queues, since we may reconnect after handover
* failure. the buffered messages is replaced there */
/* send RELEASE INDICATION to L3 */
send_dl_simple(PRIM_DL_REL, PRIM_OP_INDICATION,
&dl->lctx);
/* send MDL ERROR INIDCATION to L3 */
mdl_error(MDL_CAUSE_T200_EXPIRED, &dl->lctx);
break;
}
/* retransmit SABM command */