From 5f0c71b7d5c38dcd5eecd2836a86cb9b4768a759 Mon Sep 17 00:00:00 2001 From: Neels Hofmeyr Date: Sat, 23 Jul 2016 20:15:28 +0200 Subject: dyn TS: OS#1778 workaround: disable TCH/F on dyn TS for nitb To avoid two phones picking mismatching TCH pchans, never pick TCH/F on dynamic TS in osmo-nitb. Add gsm_network flag dyn_ts_allow_tch_f, set to true by default in gsm_network_init(). Set this flag to false in osmo-nitb's main(). See http://osmocom.org/issues/1778 Reasoning about ways to solve this: * a compile time switch doesn't work because libbsc is first compiled and then linked to both osmo-nitb and osmo-bsc. * we could test net->bsc_api == msc_bsc_api(), but I have the so-called MSC split waiting on branch sysmocom/cscn, which will result in msc_bsc_api() not being linked in the osmo-bsc binary. * have a function am_i_nitb() with different implementations in osmo-nitb and osmo-bsc, but then we'd need to add implementations to all tests and other binaries linking lchan_alloc(). * have a flag in struct bsc_api, but so far there are only function pointers there. Having a "global" flag in gsm_network allows to add a VTY command in case we decide to keep this feature (#1781), has no linking implications and is nicely explicit. Tested that osmo-bsc still picks TCH/F on dyn TS indirectly, since I have no standalone MSC available: when compiling osmo-nitb with the line that sets dyn_ts_allow_tch_f = false commented out, TCH/F is picked as described in OS#1778; and by printf-verifying that dyn_ts_allow_tch_f == true in osmo-bsc main(), only osmo-nitb should have TCH/F disabled. Related: OS#1778, OS#1781 Change-Id: If7e4797a72815fc6e2bbef27756ea5df69f4bde7 --- openbsc/src/libbsc/chan_alloc.c | 3 ++- openbsc/src/libbsc/net_init.c | 2 ++ 2 files changed, 4 insertions(+), 1 deletion(-) (limited to 'openbsc/src/libbsc') diff --git a/openbsc/src/libbsc/chan_alloc.c b/openbsc/src/libbsc/chan_alloc.c index 1e5dd74cd..c3a7e0f04 100644 --- a/openbsc/src/libbsc/chan_alloc.c +++ b/openbsc/src/libbsc/chan_alloc.c @@ -309,8 +309,9 @@ struct gsm_lchan *lchan_alloc(struct gsm_bts *bts, enum gsm_chan_t type, if (lchan) type = GSM_LCHAN_TCH_F; } + /* Try fully dynamic TCH/F_TCH/H_PDCH as TCH/F... */ - if (!lchan) { + if (!lchan && bts->network->dyn_ts_allow_tch_f) { lchan = _lc_dyn_find_bts(bts, GSM_PCHAN_TCH_F_TCH_H_PDCH, GSM_PCHAN_TCH_F); diff --git a/openbsc/src/libbsc/net_init.c b/openbsc/src/libbsc/net_init.c index ee0d445cd..6d03ee428 100644 --- a/openbsc/src/libbsc/net_init.c +++ b/openbsc/src/libbsc/net_init.c @@ -116,6 +116,8 @@ struct gsm_network *gsm_network_init(uint16_t country_code, uint16_t network_cod net->ext_max = GSM_MAX_EXTEN; gsm_net_update_ctype(net); + net->dyn_ts_allow_tch_f = true; + return net; } -- cgit v1.2.3