bsc_api.c: Documentation for handle_mr_config()
Change-Id: I6edd442afc7c20f8f097198941bc592d429ba5da
diff --git a/openbsc/src/libbsc/bsc_api.c b/openbsc/src/libbsc/bsc_api.c
index 4dba3e9..7613cac 100644
--- a/openbsc/src/libbsc/bsc_api.c
+++ b/openbsc/src/libbsc/bsc_api.c
@@ -151,8 +151,13 @@
api->assign_fail(conn, GSM0808_CAUSE_NO_RADIO_RESOURCE_AVAILABLE, NULL);
}
-/**
- * Handle the multirate config
+/*! \brief Determine and apply AMR multi-rate configuration to lchan
+ * Determine which AMR multi-rate configuration to use and apply it to
+ * the lchan (so it can be communicated to BTS and MS during channel
+ * activation.
+ * \param[in] conn subscriber connection (used to resolve bsc_api)
+ * \param[out] lchan logical channel to which to apply mr config
+ * \param[in] full_rate whether to use full-rate (1) or half-rate (0) config
*/
static void handle_mr_config(struct gsm_subscriber_connection *conn,
struct gsm_lchan *lchan, int full_rate)
@@ -162,9 +167,13 @@
struct amr_multirate_conf *mr;
struct gsm48_multi_rate_conf *mr_conf;
+ /* BSC api override for this method, used in OsmoBSC mode with
+ * bsc_mr_config() to use MSC-specific/specified configuration */
if (api->mr_config)
return api->mr_config(conn, lchan, full_rate);
+ /* NITB case: use the BTS-specic multi-rate configuration from
+ * the vty/configuration file */
if (full_rate)
mr = &lchan->ts->trx->bts->mr_full;
else
@@ -178,6 +187,8 @@
mr_conf->icmi = 1;
mr_conf->m5_90 = 1;
}
+ /* store encoded MR config IE lchan for both MS (uplink) and BTS
+ * (downlink) directions */
gsm48_multirate_config(lchan->mr_ms_lv, mr, mr->ms_mode);
gsm48_multirate_config(lchan->mr_bts_lv, mr, mr->bts_mode);
}