From ad7277073c1a8e24a24969ee38747a7cc74dcd1b Mon Sep 17 00:00:00 2001 From: Philipp Maier Date: Thu, 3 May 2018 19:03:03 +0200 Subject: bsc_api/GSCON: prevent unnecessary channel mode modifications gsm0808_assign_req() checks if the new channel mode is compatible with the new mode. If it is, it does a gsm48_lchan_modify(), but it does not actually check if the new mode is equal to the current mode. - skip when the channel is compatible and the new mode is equal to the old mode. - send the ASSIGNMENT COMPLETE directly from ST_ACTIVE when no mode modify was necessary. Change-Id: I86a2d52836c54d2dbd77441b182f757327ec7262 Related: OS#2936 --- src/libbsc/bsc_api.c | 22 ++++++++++++++-------- src/libbsc/bsc_subscr_conn_fsm.c | 6 +++++- 2 files changed, 19 insertions(+), 9 deletions(-) diff --git a/src/libbsc/bsc_api.c b/src/libbsc/bsc_api.c index 142efef02..19859cf8a 100644 --- a/src/libbsc/bsc_api.c +++ b/src/libbsc/bsc_api.c @@ -296,16 +296,17 @@ static int chan_compat_with_mode(struct gsm_lchan *lchan, int chan_mode, int ful } } -/** - * Send a GSM08.08 Assignment Request. Right now this does not contain the - * audio codec type or the allowed rates for the config. It is assumed that - * this is for audio handling only. In case the current channel does not allow - * the selected mode a new one will be allocated. - * - * TODO: Add multirate configuration, make it work for more than audio. - */ +/*! Send a GSM08.08 Assignment Request. Right now this does not contain the + * audio codec type or the allowed rates for the config. In case the current + * channel does not allow the selected mode a new one will be allocated. + * \param[out] conn related subscriber connection + * \param[in] chan_mode mode of the channel (see enum gsm48_chan_mode) + * \param[in] full_rate select full rate or half rate channel + * \returns 0 on success, 1 when no operation is neccessary, -1 on failure */ int gsm0808_assign_req(struct gsm_subscriber_connection *conn, int chan_mode, int full_rate) { + /* TODO: Add multirate configuration, make it work for more than audio. */ + struct bsc_api *api; api = conn->network->bsc_api; @@ -313,6 +314,11 @@ int gsm0808_assign_req(struct gsm_subscriber_connection *conn, int chan_mode, in if (handle_new_assignment(conn, chan_mode, full_rate) != 0) goto error; } else { + /* Check if the channel is already in the requested mode, if + * yes, we skip unnecessary channel mode modify operations. */ + if (conn->lchan->tch_mode == chan_mode) + return 1; + if (chan_mode == GSM48_CMODE_SPEECH_AMR) handle_mr_config(conn, conn->lchan, full_rate); diff --git a/src/libbsc/bsc_subscr_conn_fsm.c b/src/libbsc/bsc_subscr_conn_fsm.c index b5e7e7d8e..7f53f1b8a 100644 --- a/src/libbsc/bsc_subscr_conn_fsm.c +++ b/src/libbsc/bsc_subscr_conn_fsm.c @@ -438,7 +438,11 @@ static void gscon_fsm_active(struct osmo_fsm_inst *fi, uint32_t event, void *dat * change back to ST_ACTIVE (here) immediately. */ rc = gsm0808_assign_req(conn, conn->user_plane.chan_mode, conn->user_plane.full_rate); - if (rc != 0) { + + if (rc == 1) { + send_ass_compl(conn->lchan, fi, false); + return; + } else if (rc != 0) { resp = gsm0808_create_assignment_failure(GSM0808_CAUSE_EQUIPMENT_FAILURE, NULL); sigtran_send(conn, resp, fi); return; -- cgit v1.2.3