fixeria has uploaded this change for review.
assignment_fsm: check ipaccess channel mode support
Add ipacc_chan_mode_supported(), which checks the NM_IPAC_F_CHANM_*
flags stored in the Baseband Transceiver's MO state (populated during
OML bring-up) to decide whether the BTS can handle a requested channel
mode. If the IE containing supported channel modes was never received,
the function returns true as if the given mode was supported.
Without this change, requesting a channel mode not supported by the
BTS results in a NACK to the RSL Channel Activation, which causes
the lchan to be marked as BROKEN and thus unavailable.
Change-Id: I680ba7993786f5486d671f931e75df4543670a37
Related: OS#6324
---
M src/osmo-bsc/assignment_fsm.c
1 file changed, 102 insertions(+), 3 deletions(-)
git pull ssh://gerrit.osmocom.org:29418/osmo-bsc refs/changes/90/42590/1
diff --git a/src/osmo-bsc/assignment_fsm.c b/src/osmo-bsc/assignment_fsm.c
index 11408d6..54a57aa 100644
--- a/src/osmo-bsc/assignment_fsm.c
+++ b/src/osmo-bsc/assignment_fsm.c
@@ -365,6 +365,86 @@
new_lchan->ts->max_primary_lchans : 0));
}
+/* Check whether the ipaccess BTS supports the requested channel mode.
+ * Returns false if the BTS has reported its supported channel modes and the
+ * requested mode is absent from that list. Returns true if the Supported
+ * Features IE was never received (older osmo-bts versions do not send it). */
+static bool ipacc_chan_mode_supported(const struct gsm_lchan *lchan,
+ const struct channel_mode_and_rate *ch_mode_rate)
+{
+ const struct ipacc_supp_feat *feat =
+ &lchan->ts->trx->bb_transc.mo.ipaccess.chan_modes;
+ uint32_t flag = 0;
+
+ /* Supported Features IE was not received */
+ if (!feat->present)
+ return true;
+
+ switch (gsm48_chan_mode_to_non_vamos(ch_mode_rate->chan_mode)) {
+ case GSM48_CMODE_SPEECH_V1:
+ flag = (lchan->type == GSM_LCHAN_TCH_H)
+ ? NM_IPAC_F_CHANM_SPEECH_HS : NM_IPAC_F_CHANM_SPEECH_FS;
+ break;
+ case GSM48_CMODE_SPEECH_EFR:
+ flag = NM_IPAC_F_CHANM_SPEECH_EFS;
+ break;
+ case GSM48_CMODE_SPEECH_AMR:
+ flag = (lchan->type == GSM_LCHAN_TCH_H)
+ ? NM_IPAC_F_CHANM_SPEECH_AHS : NM_IPAC_F_CHANM_SPEECH_AFS;
+ break;
+ case GSM48_CMODE_DATA_3k6:
+ case GSM48_CMODE_DATA_6k0:
+ case GSM48_CMODE_DATA_12k0:
+ case GSM48_CMODE_DATA_14k5:
+ if (ch_mode_rate->data_transparent) {
+ switch (ch_mode_rate->data_rate.t) {
+ case RSL_CMOD_CSD_T_1200_75:
+ flag = NM_IPAC_F_CHANM_CSD_T_1200_75;
+ break;
+ case RSL_CMOD_CSD_T_600:
+ flag = NM_IPAC_F_CHANM_CSD_T_600;
+ break;
+ case RSL_CMOD_CSD_T_1k2:
+ flag = NM_IPAC_F_CHANM_CSD_T_1k2;
+ break;
+ case RSL_CMOD_CSD_T_2k4:
+ flag = NM_IPAC_F_CHANM_CSD_T_2k4;
+ break;
+ case RSL_CMOD_CSD_T_4k8:
+ flag = NM_IPAC_F_CHANM_CSD_T_4k8;
+ break;
+ case RSL_CMOD_CSD_T_9k6:
+ flag = NM_IPAC_F_CHANM_CSD_T_9k6;
+ break;
+ case RSL_CMOD_CSD_T_14k4:
+ flag = NM_IPAC_F_CHANM_CSD_T_14k4;
+ break;
+ default:
+ return true; /* unhandled T rate */
+ }
+ } else {
+ switch (ch_mode_rate->data_rate.nt) {
+ case RSL_CMOD_CSD_NT_6k0:
+ flag = NM_IPAC_F_CHANM_CSD_NT_4k8;
+ break;
+ case RSL_CMOD_CSD_NT_12k0:
+ flag = NM_IPAC_F_CHANM_CSD_NT_9k6;
+ break;
+ case RSL_CMOD_CSD_NT_14k5:
+ flag = NM_IPAC_F_CHANM_CSD_NT_14k4;
+ break;
+ default:
+ return true; /* unhandled NT rate */
+ }
+ }
+ break;
+ default:
+ return true; /* unknown channel mode */
+ }
+
+ return (feat->val & flag) != 0;
+}
+
static bool lchan_type_compat_with_mode(const struct gsm_lchan *lchan,
const struct channel_mode_and_rate *ch_mode_rate)
{
@@ -373,6 +453,8 @@
switch (gsm48_chan_mode_to_non_vamos(chan_mode)) {
case GSM48_CMODE_SIGN:
+ /* Signalling does not require a specific channel mode on the BTS,
+ * so skip the ipaccess feature check (below) and return directly. */
switch (lchan->type) {
case GSM_LCHAN_TCH_F: return chan_rate == CH_RATE_FULL;
case GSM_LCHAN_TCH_H: return chan_rate == CH_RATE_HALF;
@@ -388,22 +470,39 @@
* an explicit override by the 'chan_rate' argument */
switch (lchan->type) {
case GSM_LCHAN_TCH_F:
- return chan_rate == CH_RATE_FULL;
+ if (chan_rate != CH_RATE_FULL)
+ return false;
+ break;
case GSM_LCHAN_TCH_H:
- return chan_rate == CH_RATE_HALF;
+ if (chan_rate != CH_RATE_HALF)
+ return false;
+ break;
default:
return false;
}
+ break;
case GSM48_CMODE_DATA_12k0:
case GSM48_CMODE_DATA_14k5:
case GSM48_CMODE_SPEECH_EFR:
/* these services all explicitly require a TCH/F */
- return lchan->type == GSM_LCHAN_TCH_F;
+ if (lchan->type != GSM_LCHAN_TCH_F)
+ return false;
+ break;
default:
return false;
}
+
+ switch (lchan->ts->trx->bts->type) {
+ case GSM_BTS_TYPE_NANOBTS:
+ case GSM_BTS_TYPE_OSMOBTS:
+ /* osmo-bts and nanoBTS report supported channel modes during
+ * the OML bring-up - additionally check them */
+ return ipacc_chan_mode_supported(lchan, ch_mode_rate);
+ default:
+ return true;
+ }
}
static __attribute__((constructor)) void assignment_fsm_init(void)
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