diff options
Diffstat (limited to 'src/osmo-bsc/lchan_select.c')
| -rw-r--r-- | src/osmo-bsc/lchan_select.c | 59 |
1 files changed, 48 insertions, 11 deletions
diff --git a/src/osmo-bsc/lchan_select.c b/src/osmo-bsc/lchan_select.c index efa2ff29b..3618fb4e8 100644 --- a/src/osmo-bsc/lchan_select.c +++ b/src/osmo-bsc/lchan_select.c @@ -30,22 +30,36 @@ #include <osmocom/bsc/lchan_select.h> #include <osmocom/bsc/bts.h> +static struct gsm_lchan *pick_better_lchan(struct gsm_lchan *a, struct gsm_lchan *b) +{ + if (!a) + return b; + if (!b) + return a; + /* comparing negative dBm values: smaller value means less interference. */ + if (b->interf_dbm < a->interf_dbm) + return b; + return a; +} + static struct gsm_lchan * _lc_find_trx(struct gsm_bts_trx *trx, enum gsm_phys_chan_config pchan, enum gsm_phys_chan_config as_pchan, bool allow_pchan_switch, bool log) { struct gsm_lchan *lchan; + struct gsm_lchan *found_lchan = NULL; struct gsm_bts_trx_ts *ts; int j, start, stop, dir; -#define LOGPLCHANALLOC(fmt, args...) \ +#define LOGPLCHANALLOC(fmt, args...) do { \ if (log) \ LOGP(DRLL, LOGL_DEBUG, "looking for lchan %s%s%s%s: " fmt, \ gsm_pchan_name(pchan), \ pchan == as_pchan ? "" : " as ", \ pchan == as_pchan ? "" : gsm_pchan_name(as_pchan), \ ((pchan != as_pchan) && !allow_pchan_switch) ? " without pchan switch" : "", \ - ## args) + ## args); \ + } while (0) if (!trx_is_usable(trx)) { LOGPLCHANALLOC("%s trx not usable\n", gsm_trx_name(trx)); @@ -87,20 +101,43 @@ _lc_find_trx(struct gsm_bts_trx *trx, enum gsm_phys_chan_config pchan, /* TS is (going to be) in desired pchan mode. Go ahead and check for an available lchan. */ lchans_as_pchan = pchan_subslots(as_pchan); ts_for_n_lchans(lchan, ts, lchans_as_pchan) { - if (lchan->fi->state == LCHAN_ST_UNUSED) { - LOGPLCHANALLOC("%s ss=%d is available%s\n", + struct gsm_lchan *was = found_lchan; + + if (lchan->fi->state != LCHAN_ST_UNUSED) { + LOGPLCHANALLOC("%s ss=%d in type=%s,state=%s not suitable\n", gsm_ts_and_pchan_name(ts), lchan->nr, - ts->pchan_is != as_pchan ? " after dyn PCHAN change" : ""); - return lchan; + gsm_lchant_name(lchan->type), + osmo_fsm_inst_state_name(lchan->fi)); + continue; } - LOGPLCHANALLOC("%s ss=%d in type=%s,state=%s not suitable\n", - gsm_ts_and_pchan_name(ts), lchan->nr, - gsm_lchant_name(lchan->type), - osmo_fsm_inst_state_name(lchan->fi)); + + found_lchan = pick_better_lchan(found_lchan, lchan); + if (found_lchan != was) + LOGPLCHANALLOC("%s ss=%d interf=%u=%ddBm is %s%s\n", + gsm_ts_and_pchan_name(ts), lchan->nr, + lchan->interf_band, lchan->interf_dbm, + was == NULL ? "available" : "better", + ts->pchan_is != as_pchan ? ", after dyn PCHAN change" : ""); + else + LOGPLCHANALLOC("%s ss=%d interf=%u=%ddBm is also available but not better\n", + gsm_ts_and_pchan_name(ts), lchan->nr, + lchan->interf_band, lchan->interf_dbm); + + /* When picking an lchan with least interference, continue to loop across all lchans. When + * ignoring interference levels, return the first match. */ + if (found_lchan && !trx->bts->chan_alloc_avoid_interf) + return found_lchan; } } - return NULL; + if (found_lchan) + LOGPLCHANALLOC("%s ss=%d interf=%ddBm%s is the best pick\n", + gsm_ts_and_pchan_name(found_lchan->ts), found_lchan->nr, + found_lchan->interf_dbm, + found_lchan->ts->pchan_is != as_pchan ? ", after dyn PCHAN change," : ""); + else + LOGPLCHANALLOC("Nothing found"); + return found_lchan; #undef LOGPLCHANALLOC } |