neels has uploaded this change for review. ( https://gerrit.osmocom.org/c/osmo-bts/+/35095?usp=email )

Change subject: early-IA: use the correct TRX ......................................................................

early-IA: use the correct TRX

Change-Id: Id9a930e5c67122812b229dc27ea2bfe246b67611 --- M src/common/rsl.c 1 file changed, 43 insertions(+), 9 deletions(-)

git pull ssh://gerrit.osmocom.org:29418/osmo-bts refs/changes/95/35095/1

diff --git a/src/common/rsl.c b/src/common/rsl.c index deeb255..9405c6e 100644 --- a/src/common/rsl.c +++ b/src/common/rsl.c @@ -371,6 +371,16 @@ return true; }

+static struct gsm_bts_trx *trx_lookup_by_arfcn(struct llist_head *trx_list, uint16_t arfcn) +{ + struct gsm_bts_trx *trx; + llist_for_each_entry(trx, trx_list, list) { + if (trx->arfcn == arfcn) + return trx; + } + return NULL; +} + static struct gsm_lchan *lchan_lookup(struct gsm_bts_trx *trx, uint8_t chan_nr, const char *log_name) { @@ -1383,18 +1393,33 @@ * the channel is active. Hence we still wait for the activation, but don't need the Abis roundtrip of Activ ACK * -> Immediate Assignment via the BSC. * If anything is wrong with the sizes or the lchan lookup, behave normally, i.e. do not do the RR IA caching, - * but just send the RR message to the MS as-is. */ + * but just send the RR message to the MS as-is. + * 'trx' here is the TRX of the BCCH channel. To find the correct TRX for the IMM ASS target, we need to look up + * the ARFCN that is contained in the IMM ASS message. When frequency hopping is enabled, there will not be an + * ARFCN, so we cannot support early-IA with frequency hopping enabled. */ if (msg->len >= sizeof(struct gsm48_imm_ass)) { struct gsm48_imm_ass *rr_ia = (void*)msg->data; - struct gsm_lchan *ia_target_lchan = lchan_lookup(trx, rr_ia->chan_desc.chan_nr, "Early IA check: "); - if (ia_target_lchan && ia_target_lchan->state != LCHAN_S_ACTIVE) { - /* Target lchan is not yet active. Cache the IA. - * If a previous IA is still lingering, free it. */ - msgb_free(ia_target_lchan->early_rr_ia); - ia_target_lchan->early_rr_ia = msg; + if (rr_ia->chan_desc.h0.h == 0) { + /* hopping is disabled. */ + struct gsm_bts_trx *ia_target_trx; + uint16_t arfcn; + arfcn = (rr_ia->chan_desc.h0.arfcn_high << 8) + rr_ia->chan_desc.h0.arfcn_low;

- /* return 1 means: don't msgb_free() the msg */ - return 1; + ia_target_trx = trx_lookup_by_arfcn(&trx->bts->trx_list, arfcn); + if (ia_target_trx) { + /* found the ARFCN's trx */ + struct gsm_lchan *ia_target_lchan; + ia_target_lchan = lchan_lookup(ia_target_trx, rr_ia->chan_desc.chan_nr, "Early IA check: "); + if (ia_target_lchan && ia_target_lchan->state != LCHAN_S_ACTIVE) { + /* Target lchan is not yet active. Cache the IA. + * If a previous IA is still lingering, free it. */ + msgb_free(ia_target_lchan->early_rr_ia); + ia_target_lchan->early_rr_ia = msg; + + /* return 1 means: don't msgb_free() the msg */ + return 1; + } + } } }