Change in ...osmo-bts[master]: osmo-bts-trx/scheduler: fix: do not reset ECU with BFI frame

[fixeria]

fixeria has uploaded this change for review. ( https://gerrit.osmocom.org/c/osmo-bts/+/15441


Change subject: osmo-bts-trx/scheduler: fix: do not reset ECU with BFI frame
......................................................................

osmo-bts-trx/scheduler: fix: do not reset ECU with BFI frame

BFI (Bad Frame Indication) needs to be sent:

  - when failed to decode a speech (or FACCH) frame, or
  - when decoded frame is FACCH frame (23 octets long),

if the current channel mode is RSL_CMOD_SPD_SPEECH.

Since we (re)use the same buffer as used for non-BFI frames,
we need to avoid resetting the ECU (Error Cancellation Unit)
with a bad frame indication.

We used a boolean flag for that, but it was not set in the
second case - when a FACCH frame is decoded. Let's get rid
of that flag and use 'goto' operator to step over the ECU
resetting code.

Let's also modify rx_tchh_fn(), which does not (yet) deal
with ECU, but most likely will in the future.

Change-Id: I8bdc7483f524006a86ff1fee7cdefafe3db899d8
---
M src/osmo-bts-trx/scheduler_trx.c
1 file changed, 7 insertions(+), 4 deletions(-)



  git pull ssh://gerrit.osmocom.org:29418/osmo-bts refs/changes/41/15441/1

diff --git a/src/osmo-bts-trx/scheduler_trx.c b/src/osmo-bts-trx/scheduler_trx.c
index 57eb138..5b31387 100644
--- a/src/osmo-bts-trx/scheduler_trx.c
+++ b/src/osmo-bts-trx/scheduler_trx.c
@@ -1138,7 +1138,6 @@
 	uint8_t tch_data[128]; /* just to be safe */
 	int rc, amr = 0;
 	int n_errors, n_bits_total;
-	bool bfi_flag = false;
 	struct gsm_lchan *lchan =
 		get_lchan_by_chan_nr(l1t->trx, trx_chan_desc[chan].chan_nr | bi->tn);
 
@@ -1235,14 +1234,12 @@
 		LOGL1S(DL1P, LOGL_NOTICE, l1t, bi->tn, chan, bi->fn,
 			"Received bad data (%u/%u)\n",
 			bi->fn % l1ts->mf_period, l1ts->mf_period);
-		bfi_flag = true;
 		goto bfi;
 	}
 	if (rc < 4) {
 		LOGL1S(DL1P, LOGL_NOTICE, l1t, bi->tn, chan, bi->fn,
 			"Received bad data (%u/%u) with invalid codec mode %d\n",
 			bi->fn % l1ts->mf_period, l1ts->mf_period, rc);
-		bfi_flag = true;
 		goto bfi;
 	}
 
@@ -1300,6 +1297,9 @@
 					"TCH mode %u invalid, please fix!\n", tch_mode);
 				return -EINVAL;
 			}
+
+			/* Step over resetting ECU */
+			goto compose_l1sap;
 		}
 	}
 
@@ -1307,7 +1307,7 @@
 		return 0;
 
 	/* Reset ECU with a good frame */
-	if (!bfi_flag && tch_mode == GSM48_CMODE_SPEECH_V1)
+	if (tch_mode == GSM48_CMODE_SPEECH_V1)
 		osmo_ecu_fr_reset(&lchan->ecu_state.fr, tch_data);
 
 	/* TCH or BFI */
@@ -1497,6 +1497,9 @@
 					"TCH mode %u invalid, please fix!\n", tch_mode);
 				return -EINVAL;
 			}
+
+			/* Step over resetting ECU */
+			goto compose_l1sap;
 		}
 	}
 

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Gerrit-Project: osmo-bts
Gerrit-Branch: master
Gerrit-Change-Id: I8bdc7483f524006a86ff1fee7cdefafe3db899d8
Gerrit-Change-Number: 15441
Gerrit-PatchSet: 1
Gerrit-Owner: fixeria <axilirator at gmail.com>
Gerrit-MessageType: newchange
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