From 4b4dd100f8ca079134b780e0ca0879c1ab3e5ebb Mon Sep 17 00:00:00 2001 From: Holger Hans Peter Freyther Date: Mon, 31 May 2010 21:38:24 +0800 Subject: [rsl] Introduce an error state for the lchan and set it on release When we issue a RF Channel Release in case of a failure we receive RLL release indications after the channel was tearn down and we issue another RF Channel Release as a result. The channel allocator might have already allocated this channel and we release the channel again with another MS on it. Make rsl_rf_chan_release take an error argument and make it set a new state in case of an error and change the RF Channel Release ack to not set the state back to none in case of an error but wait for a timeout that is a bit higher than T3111. I tested this with removing the battery during a phonecall and waiting for the channel failure. With this test we only send the release once. --- openbsc/src/abis_rsl.c | 54 +++++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 45 insertions(+), 9 deletions(-) (limited to 'openbsc/src/abis_rsl.c') diff --git a/openbsc/src/abis_rsl.c b/openbsc/src/abis_rsl.c index d170ff78f..79c8eeb37 100644 --- a/openbsc/src/abis_rsl.c +++ b/openbsc/src/abis_rsl.c @@ -568,12 +568,33 @@ int rsl_deact_sacch(struct gsm_lchan *lchan) return abis_rsl_sendmsg(msg); } +static void error_timeout_cb(void *data) +{ + struct gsm_lchan *lchan = data; + if (lchan->state != LCHAN_S_REL_ERR) { + LOGP(DRSL, LOGL_ERROR, "%s error timeout but not in error state: %d\n", + gsm_lchan_name(lchan), lchan->state); + return; + } + + /* go back to the none state */ + LOGP(DRSL, LOGL_NOTICE, "%s is back in operation.\n", gsm_lchan_name(lchan)); + lchan->state = LCHAN_S_NONE; +} + /* Chapter 8.4.14 / 4.7: Tell BTS to release the radio channel */ -int rsl_rf_chan_release(struct gsm_lchan *lchan) +static int rsl_rf_chan_release(struct gsm_lchan *lchan, int error) { struct abis_rsl_dchan_hdr *dh; - struct msgb *msg = rsl_msgb_alloc(); + struct msgb *msg; + + if (lchan->state == LCHAN_S_REL_ERR) { + LOGP(DRSL, LOGL_NOTICE, "%s is in error state not sending release.\n", + gsm_lchan_name(lchan)); + return -1; + } + msg = rsl_msgb_alloc(); dh = (struct abis_rsl_dchan_hdr *) msgb_put(msg, sizeof(*dh)); init_dchan_hdr(dh, RSL_MT_RF_CHAN_REL); dh->chan_nr = lchan2chan_nr(lchan); @@ -581,7 +602,20 @@ int rsl_rf_chan_release(struct gsm_lchan *lchan) msg->lchan = lchan; msg->trx = lchan->ts->trx; - DEBUGP(DRSL, "%s RF Channel Release CMD\n", gsm_lchan_name(lchan)); + DEBUGP(DRSL, "%s RF Channel Release CMD due error %d\n", gsm_lchan_name(lchan), error); + + if (error) { + /* + * the nanoBTS sends RLL release indications after the channel release. This can + * be a problem when we have reassigned the channel to someone else and then can + * not figure out who used this channel. + */ + lchan->state = LCHAN_S_REL_ERR; + lchan->error_timer.data = lchan; + lchan->error_timer.cb = error_timeout_cb; + bsc_schedule_timer(&lchan->error_timer, + msg->trx->bts->network->T3111 + 2, 0); + } /* BTS will respond by RF CHAN REL ACK */ return abis_rsl_sendmsg(msg); @@ -811,7 +845,7 @@ static int rsl_rx_conn_fail(struct msgb *msg) LOGPC(DRSL, LOGL_NOTICE, "\n"); /* FIXME: only free it after channel release ACK */ counter_inc(msg->lchan->ts->trx->bts->network->stats.chan.rf_fail); - return rsl_rf_chan_release(msg->lchan); + return rsl_rf_chan_release(msg->lchan, 1); } static void print_meas_rep_uni(struct gsm_meas_rep_unidir *mru, @@ -983,12 +1017,14 @@ static int abis_rsl_rx_dchan(struct msgb *msg) break; case RSL_MT_RF_CHAN_REL_ACK: DEBUGP(DRSL, "%s RF CHANNEL RELEASE ACK\n", ts_name); - if (msg->lchan->state != LCHAN_S_REL_REQ) + if (msg->lchan->state != LCHAN_S_REL_REQ && msg->lchan->state != LCHAN_S_REL_ERR) LOGP(DRSL, LOGL_NOTICE, "%s CHAN REL ACK but state %s\n", gsm_lchan_name(msg->lchan), gsm_lchans_name(msg->lchan->state)); bsc_del_timer(&msg->lchan->T3111); - rsl_lchan_set_state(msg->lchan, LCHAN_S_NONE); + /* we have an error timer pending to release that */ + if (msg->lchan->state != LCHAN_S_REL_ERR) + rsl_lchan_set_state(msg->lchan, LCHAN_S_NONE); lchan_free(msg->lchan); break; case RSL_MT_MODE_MODIFY_ACK: @@ -1080,7 +1116,7 @@ static void t3101_expired(void *data) { struct gsm_lchan *lchan = data; - rsl_rf_chan_release(lchan); + rsl_rf_chan_release(lchan, 1); } /* If T3111 expires, we will send the RF Channel Request */ @@ -1088,7 +1124,7 @@ static void t3111_expired(void *data) { struct gsm_lchan *lchan = data; - rsl_rf_chan_release(lchan); + rsl_rf_chan_release(lchan, 0); } /* MS has requested a channel on the RACH */ @@ -1261,7 +1297,7 @@ static int rsl_rx_rll_err_ind(struct msgb *msg) if (rlm_cause[1] == RLL_CAUSE_T200_EXPIRED) { counter_inc(msg->lchan->ts->trx->bts->network->stats.chan.rll_err); - return rsl_rf_chan_release(msg->lchan); + return rsl_rf_chan_release(msg->lchan, 1); } return 0; -- cgit v1.2.3