rsl_tx_rf_res(): separate interference AVG / band calculation

It's cleaner from the architectural point of view to have the
interference measurements processed in a separate function.

Change-Id: I3981608e01a50585359cad673c38c8a305027d30
Related: SYS#5313

4 files changed, 43 insertions, 18 deletions

diff --git a/include/osmo-bts/lchan.h b/include/osmo-bts/lchan.h
index fdb3144c..8fcf36aa 100644
--- a/include/osmo-bts/lchan.h
+++ b/include/osmo-bts/lchan.h
@@ -226,8 +226,10 @@ struct gsm_lchan {
 			uint16_t toa256_std_dev;
 		} ext;
 		/* Interference levels reported by PHY (in dBm) */
+		int16_t interf_meas_avg_dbm; /* Average value */
 		int16_t interf_meas_dbm[31]; /* Intave max is 31 */
 		uint8_t interf_meas_num;
+		uint8_t interf_band;
 	} meas;
 	struct {
 		struct amr_multirate_conf amr_mr;
@@ -341,7 +343,7 @@ uint8_t gsm_lchan_as_pchan2chan_nr(const struct gsm_lchan *lchan,
 				   enum gsm_phys_chan_config as_pchan);
 
 void gsm_lchan_interf_meas_push(struct gsm_lchan *lchan, int dbm);
-int gsm_lchan_interf_meas_calc_band(struct gsm_lchan *lchan);
+void gsm_lchan_interf_meas_calc_avg(struct gsm_lchan *lchan);
 
 int lchan2ecu_codec(const struct gsm_lchan *lchan);
 
diff --git a/src/common/l1sap.c b/src/common/l1sap.c
index a48287c5..5c58aff7 100644
--- a/src/common/l1sap.c
+++ b/src/common/l1sap.c
@@ -591,6 +591,29 @@ static unsigned int calc_exprd_rach_frames(struct gsm_bts *bts, uint32_t fn)
 	return rach_frames_expired;
 }
 
+static void l1sap_interf_meas_calc_avg(struct gsm_bts_trx *trx)
+{
+	unsigned int tn, ln;
+
+	for (tn = 0; tn < ARRAY_SIZE(trx->ts); tn++) {
+		struct gsm_bts_trx_ts *ts = &trx->ts[tn];
+
+		for (ln = 0; ln < ARRAY_SIZE(ts->lchan); ln++) {
+			struct gsm_lchan *lchan = &ts->lchan[ln];
+
+			lchan->meas.interf_meas_avg_dbm = 0;
+			lchan->meas.interf_band = 0;
+
+			/* There must be at least one sample */
+			if (lchan->meas.interf_meas_num == 0)
+				continue;
+
+			/* Average all collected samples */
+			gsm_lchan_interf_meas_calc_avg(lchan);
+		}
+	}
+}
+
 static void l1sap_interf_meas_report(struct gsm_bts *bts)
 {
 	const uint32_t period = bts->interference.intave * 104;
@@ -601,8 +624,12 @@ static void l1sap_interf_meas_report(struct gsm_bts *bts)
 	if (bts->gsm_time.fn % period != 0)
 		return;
 
-	llist_for_each_entry(trx, &bts->trx_list, list)
+	llist_for_each_entry(trx, &bts->trx_list, list) {
+		/* Calculate the average of all received samples */
+		l1sap_interf_meas_calc_avg(trx);
+		/* Report to the BSC over the A-bis/RSL */
 		rsl_tx_rf_res(trx);
+	}
 }
 
 /* time information received from bts model */
diff --git a/src/common/lchan.c b/src/common/lchan.c
index 10a375e7..f7ee33bb 100644
--- a/src/common/lchan.c
+++ b/src/common/lchan.c
@@ -348,15 +348,14 @@ void gsm_lchan_interf_meas_push(struct gsm_lchan *lchan, int dbm)
 }
 
 /* Called by the higher layers every Intave * 104 TDMA frames */
-int gsm_lchan_interf_meas_calc_band(struct gsm_lchan *lchan)
+void gsm_lchan_interf_meas_calc_avg(struct gsm_lchan *lchan)
 {
 	const uint8_t meas_num = lchan->meas.interf_meas_num;
 	const struct gsm_bts *bts = lchan->ts->trx->bts;
 	int b, meas_avg, meas_sum = 0;
 
 	/* There must be at least one sample */
-	if (meas_num == 0)
-		return -EAGAIN;
+	OSMO_ASSERT(meas_num > 0);
 
 	/* Calculate the sum of all collected samples (in -x dBm) */
 	while (lchan->meas.interf_meas_num) {
@@ -377,7 +376,8 @@ int gsm_lchan_interf_meas_calc_band(struct gsm_lchan *lchan)
 		  "Interference AVG: %ddBm (band %d, samples %u)\n",
 		  meas_avg, b, meas_num);
 
-	return b;
+	lchan->meas.interf_meas_avg_dbm = meas_avg;
+	lchan->meas.interf_band = b;
 }
 
 /* determine the ECU codec constant for the codec used by given lchan */
diff --git a/src/common/rsl.c b/src/common/rsl.c
index 229a2afc..e4531aa1 100644
--- a/src/common/rsl.c
+++ b/src/common/rsl.c
@@ -440,29 +440,25 @@ int rsl_tx_rf_res(struct gsm_bts_trx *trx)
 	uint8_t *len = msgb_tl_put(nmsg, RSL_IE_RESOURCE_INFO);
 
 	for (tn = 0; tn < ARRAY_SIZE(trx->ts); tn++) {
-		struct gsm_bts_trx_ts *ts = &trx->ts[tn];
+		const struct gsm_bts_trx_ts *ts = &trx->ts[tn];
 
 		for (ln = 0; ln < ARRAY_SIZE(ts->lchan); ln++) {
-			struct gsm_lchan *lchan = &ts->lchan[ln];
+			const struct gsm_lchan *lchan = &ts->lchan[ln];
+
+			/* No average interference value => no band */
+			if (lchan->meas.interf_meas_avg_dbm == 0)
+				continue;
 
 			/* We're not interested in active lchans */
-			if (lchan->state == LCHAN_S_ACTIVE) {
-				/* Avoid potential buffer overflow */
-				lchan->meas.interf_meas_num = 0;
+			if (lchan->state == LCHAN_S_ACTIVE)
 				continue;
-			}
 
 			/* Only for GSM_LCHAN_{SDCCH,TCH_F,TCH_H} */
 			if (!lchan_is_dcch(lchan))
 				continue;
 
-			/* Average all collected samples */
-			int band = gsm_lchan_interf_meas_calc_band(lchan);
-			if (band < 0)
-				continue;
-
 			msgb_v_put(nmsg, gsm_lchan2chan_nr_rsl(lchan));
-			msgb_v_put(nmsg, (band & 0x07) << 5);
+			msgb_v_put(nmsg, (lchan->meas.interf_band & 0x07) << 5);
 		}
 	}