Change in osmo-bts[master]: osmo-bts-trx: drop Uplink loss detection from Downlink path - gerrit-log

6 May 2022

fixeria has submitted this change. ( https://gerrit.osmocom.org/c/osmo-bts/+/20674 )
Change subject: osmo-bts-trx: drop Uplink loss detection from Downlink path
......................................................................
osmo-bts-trx: drop Uplink loss detection from Downlink path
Attempting to detect missing Uplink frames in the *Downlink* path
is an ugly hack, that was needed before we had proper per-lchan
detection of missing bursts and NOPE indications in TRXDv1.
* [1] per-lchan detection of missing bursts was fixed in Aug 2018.
* [2] TRXDv1 support was introduced in Jul 2019.
Today is 2022 and it makes no sense to keep this hack.  Even if
the transceiver does not support TRXDv1, per-lchan detection
will compensate the missing Uplink bursts.
Change-Id: Ic292d180ba64206fb4d88adb284f9f9d058b4587
Related: [1] I70d05b67a35ddcbdd1b6394dbd7198404a440e76
Related: [2] If61c71d20d590bf07bfd019afb33000a0b6135bd
---
M include/osmo-bts/scheduler.h
M src/common/scheduler.c
M src/osmo-bts-trx/sched_lchan_tchf.c
M src/osmo-bts-trx/sched_lchan_xcch.c
M src/osmo-bts-virtual/scheduler_virtbts.c
5 files changed, 0 insertions(+), 122 deletions(-)
Approvals:
  laforge: Looks good to me, but someone else must approve
  fixeria: Looks good to me, approved
  pespin: Looks good to me, but someone else must approve
  Jenkins Builder: Verified

diff --git a/include/osmo-bts/scheduler.h b/include/osmo-bts/scheduler.h
index eab904c..51b1846 100644
--- a/include/osmo-bts/scheduler.h
+++ b/include/osmo-bts/scheduler.h
@@ -103,7 +103,6 @@
    uint8_t			ul_mask;	/* mask of received bursts */
/* loss detection */
-	uint8_t			lost_frames;	/* how many L2 frames were lost */
    uint32_t		last_tdma_fn;	/* last processed TDMA frame number */
    uint32_t		proc_tdma_fs;	/* how many TDMA frames were processed */
    uint32_t		lost_tdma_fs;	/* how many TDMA frames were lost */
diff --git a/src/common/scheduler.c b/src/common/scheduler.c
index d166909..6564e5a 100644
--- a/src/common/scheduler.c
+++ b/src/common/scheduler.c
@@ -788,9 +788,6 @@
    if (l2_len)
    	memcpy(msg->l2h, l2, l2_len);
-	if (L1SAP_IS_LINK_SACCH(trx_chan_desc[chan].link_id))
-		l1ts->chan_state[chan].lost_frames = 0;
-
    /* forward primitive */
    l1sap_up(l1ts->ts->trx, l1sap);
@@ -828,9 +825,6 @@
    if (tch_len)
    	memcpy(msg->l2h, tch, tch_len);
-	if (l1ts->chan_state[chan].lost_frames)
-		l1ts->chan_state[chan].lost_frames--;
-
    LOGL1S(DL1P, LOGL_DEBUG, l1ts, chan, l1sap->u.data.fn, "%s Rx -> RTP: %s\n",
           gsm_lchan_name(lchan), osmo_hexdump(msgb_l2(msg), msgb_l2len(msg)));
    /* forward primitive */
diff --git a/src/osmo-bts-trx/sched_lchan_tchf.c b/src/osmo-bts-trx/sched_lchan_tchf.c
index 20abfe1..6a90327 100644
--- a/src/osmo-bts-trx/sched_lchan_tchf.c
+++ b/src/osmo-bts-trx/sched_lchan_tchf.c
@@ -332,59 +332,6 @@
    uint8_t tch_mode = chan_state->tch_mode;
    struct osmo_phsap_prim *l1sap;
-	/* handle loss detection of received TCH frames */
-	if (rsl_cmode == RSL_CMOD_SPD_SPEECH
-	    && ++(chan_state->lost_frames) > 5) {
-		uint8_t tch_data[GSM_FR_BYTES];
-		int len;
-
-		LOGL1SB(DL1P, LOGL_NOTICE, l1ts, br, "Missing TCH bursts detected, sending BFI\n");
-
-		/* indicate bad frame */
-		switch (tch_mode) {
-		case GSM48_CMODE_SPEECH_V1: /* FR / HR */
-			if (br->chan != TRXC_TCHF) { /* HR */
-				tch_data[0] = 0x70; /* F = 0, FT = 111 */
-				memset(tch_data + 1, 0, 14);
-				len = 15;
-				break;
-			}
-			memset(tch_data, 0, GSM_FR_BYTES);
-			len = GSM_FR_BYTES;
-			break;
-		case GSM48_CMODE_SPEECH_EFR: /* EFR */
-			if (br->chan != TRXC_TCHF)
-				goto inval_mode1;
-			memset(tch_data, 0, GSM_EFR_BYTES);
-			len = GSM_EFR_BYTES;
-			break;
-		case GSM48_CMODE_SPEECH_AMR: /* AMR */
-			len = osmo_amr_rtp_enc(tch_data,
-				chan_state->codec[chan_state->dl_cmr],
-				chan_state->codec[chan_state->dl_ft], AMR_BAD);
-			if (len < 2) {
-				LOGL1SB(DL1P, LOGL_ERROR, l1ts, br,
-					"Failed to encode AMR_BAD frame (rc=%d), "
-					"not sending BFI\n", len);
-				len = 0;
-				break;
-			}
-			memset(tch_data + 2, 0, len - 2);
-			break;
-		default:
-inval_mode1:
-			LOGL1SB(DL1P, LOGL_ERROR, l1ts, br, "TCH mode invalid, please fix!\n");
-			len = 0;
-		}
-
-		if (len) {
-			/* Note: RSSI/ToA256 is set to 0 to indicate to the higher
-			 * layers that this is a faked tch_ind */
-			_sched_compose_tch_ind(l1ts, br->fn, br->chan,
-					       tch_data, len, 0, 10000, 0, 0, 0);
-		}
-	}
-
    /* get frame and unlink from queue */
    msg1 = _sched_dequeue_prim(l1ts, br);
    msg2 = _sched_dequeue_prim(l1ts, br);
diff --git a/src/osmo-bts-trx/sched_lchan_xcch.c b/src/osmo-bts-trx/sched_lchan_xcch.c
index 1d529f2..e936621 100644
--- a/src/osmo-bts-trx/sched_lchan_xcch.c
+++ b/src/osmo-bts-trx/sched_lchan_xcch.c
@@ -207,21 +207,6 @@
/* BURST BYPASS */
-	/* handle loss detection of SACCH */
-	if (L1SAP_IS_LINK_SACCH(trx_chan_desc[br->chan].link_id)) {
-		/* count and send BFI */
-		if (++(l1ts->chan_state[br->chan].lost_frames) > 1) {
-			/* TODO: Should we pass old TOA here? Otherwise we risk
-			 * unnecessary decreasing TA */
-
-			/* Note: RSSI is set to 0 to indicate to the higher
-			 * layers that this is a faked ph_data_ind */
-			_sched_compose_ph_data_ind(l1ts, 0, br->chan, NULL, 0,
-						   0, 0, 0, 10000,
-						   PRES_INFO_INVALID);
-		}
-	}
-
    /* allocate burst memory, if not already */
    if (!*bursts_p) {
    	*bursts_p = talloc_zero_size(l1ts, 464);
diff --git a/src/osmo-bts-virtual/scheduler_virtbts.c b/src/osmo-bts-virtual/scheduler_virtbts.c
index a9edb3a..d20cc39 100644
--- a/src/osmo-bts-virtual/scheduler_virtbts.c
+++ b/src/osmo-bts-virtual/scheduler_virtbts.c
@@ -244,53 +244,6 @@
    uint8_t rsl_cmode = chan_state->rsl_cmode;
    uint8_t tch_mode = chan_state->tch_mode;
    struct osmo_phsap_prim *l1sap;
-#if 0
-	/* handle loss detection of received TCH frames */
-	if (rsl_cmode == RSL_CMOD_SPD_SPEECH
-	 && ++(chan_state->lost_frames) > 5) {
-		uint8_t tch_data[GSM_FR_BYTES];
-		int len;
-
-		LOGL1SB(DL1P, LOGL_NOTICE, l1ts, br, "Missing TCH bursts detected, sending "
-			"BFI for %s\n", trx_chan_desc[br->chan].name);
-
-		/* indicate bad frame */
-		switch (tch_mode) {
-		case GSM48_CMODE_SPEECH_V1: /* FR / HR */
-			if (br->chan != TRXC_TCHF) { /* HR */
-				tch_data[0] = 0x70; /* F = 0, FT = 111 */
-				memset(tch_data + 1, 0, 14);
-				len = 15;
-				break;
-			}
-			memset(tch_data, 0, GSM_FR_BYTES);
-			len = GSM_FR_BYTES;
-			break;
-		case GSM48_CMODE_SPEECH_EFR: /* EFR */
-			if (br->chan != TRXC_TCHF)
-				goto inval_mode1;
-			memset(tch_data, 0, GSM_EFR_BYTES);
-			len = GSM_EFR_BYTES;
-			break;
-		case GSM48_CMODE_SPEECH_AMR: /* AMR */
-			len = amr_compose_payload(tch_data,
-				chan_state->codec[chan_state->dl_cmr],
-				chan_state->codec[chan_state->dl_ft], 1);
-			if (len < 2)
-				break;
-			memset(tch_data + 2, 0, len - 2);
-			_sched_compose_tch_ind(l1ts, 0, br->chan, tch_data, len);
-			break;
-		default:
-inval_mode1:
-			LOGP(DL1P, LOGL_ERROR, "TCH mode invalid, please "
-				"fix!\n");
-			len = 0;
-		}
-		if (len)
-			_sched_compose_tch_ind(l1ts, 0, br->chan, tch_data, len);
-	}
-#endif
/* get frame and unlink from queue */
    msg1 = _sched_dequeue_prim(l1ts, br);
-- 
To view, visit https://gerrit.osmocom.org/c/osmo-bts/+/20674
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Gerrit-Project: osmo-bts
Gerrit-Branch: master
Gerrit-Change-Id: Ic292d180ba64206fb4d88adb284f9f9d058b4587
Gerrit-Change-Number: 20674
Gerrit-PatchSet: 6
Gerrit-Owner: fixeria vyanitskiy@sysmocom.de
Gerrit-Reviewer: Jenkins Builder
Gerrit-Reviewer: dexter pmaier@sysmocom.de
Gerrit-Reviewer: fixeria vyanitskiy@sysmocom.de
Gerrit-Reviewer: laforge laforge@osmocom.org
Gerrit-Reviewer: osmith osmith@sysmocom.de
Gerrit-Reviewer: pespin pespin@sysmocom.de
Gerrit-MessageType: merged



    