From b24ef2357032c1ed25c2f95f8ca2e7b4cd013e82 Mon Sep 17 00:00:00 2001 From: Harald Welte Date: Sun, 2 Jun 2019 17:36:21 +0200 Subject: l1sap: Compute statistics on FN advance in PH-RTS.ind Let's keep some statistics about the min/max/average frame number advance that we're observing above L1SAP when comparing the time in the PH-RTS.ind and the frame number we observe in PH-DATA.ind of data that was received on the uplink. The statistics are currently only shown in the VTY, but this is a precursor to using them to correctly advance the LAPDm timers in a follow-up patch. Change-Id: I8f739fdb808a614f080afbc4654641ec3df19eb2 Related: OS#2294 Related: OS#3906 --- src/common/l1sap.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) (limited to 'src/common/l1sap.c') diff --git a/src/common/l1sap.c b/src/common/l1sap.c index 59d5b931..b730b853 100644 --- a/src/common/l1sap.c +++ b/src/common/l1sap.c @@ -719,6 +719,33 @@ int is_ccch_for_agch(struct gsm_bts_trx *trx, uint32_t fn) { return l1sap_fn2ccch_block(fn) < num_agch(trx, "PH-RTS-IND"); } +/* return the measured average of frame numbers that the RTS clock is running in advance */ +int32_t bts_get_avg_fn_advance(struct gsm_bts *bts) +{ + if (bts->fn_stats.avg_count == 0) + return 0; + return bts->fn_stats.avg256 / bts->fn_stats.avg_count; +} + +static void l1sap_update_fnstats(struct gsm_bts *bts, uint32_t rts_fn) +{ + int32_t delta = (rts_fn + GSM_HYPERFRAME - bts->gsm_time.fn) % GSM_HYPERFRAME; + + if (delta < bts->fn_stats.min) + bts->fn_stats.min = delta; + if (delta > bts->fn_stats.max) + bts->fn_stats.max = delta; + + if (bts->fn_stats.avg_count > bts->fn_stats.avg_window) { + /* reset and start old average and new sample */ + bts->fn_stats.avg256 = (bts->fn_stats.avg256 / bts->fn_stats.avg_count) + delta; + bts->fn_stats.avg_count = 2; + } else { + bts->fn_stats.avg256 += delta; + bts->fn_stats.avg_count++; + } +} + /* PH-RTS-IND prim received from bts model */ static int l1sap_ph_rts_ind(struct gsm_bts_trx *trx, struct osmo_phsap_prim *l1sap, struct ph_data_param *rts_ind) @@ -745,6 +772,8 @@ static int l1sap_ph_rts_ind(struct gsm_bts_trx *trx, DEBUGPGT(DL1P, &g_time, "Rx PH-RTS.ind chan_nr=%s link_id=0x%02xd\n", rsl_chan_nr_str(chan_nr), link_id); + l1sap_update_fnstats(trx->bts, fn); + /* reuse PH-RTS.ind for PH-DATA.req */ if (!msg) { LOGPGT(DL1P, LOGL_FATAL, &g_time, "RTS without msg to be reused. Please fix!\n"); -- cgit v1.2.3