HO: Assign SDCCH on channel request
This is needed, so channel can be negotiated before the actual channel
type is assigned.
In case there is no SDCCH available, try to assign what ever the MS requested.
If this is not possible try to assign TCH/F. If this is still not possible,
reject channel request.
Change-Id: I10fc9f60c58c6b7ed424a86ce23bf6b9802c9eb1
diff --git a/src/libbsc/abis_rsl.c b/src/libbsc/abis_rsl.c
index 980b3e6..64e5c92 100644
--- a/src/libbsc/abis_rsl.c
+++ b/src/libbsc/abis_rsl.c
@@ -1890,8 +1890,26 @@
*/
is_lu = !!(chreq_reason == GSM_CHREQ_REASON_LOCATION_UPD);
- /* check availability / allocate channel */
- lchan = lchan_alloc(bts, lctype, is_lu);
+ /* check availability / allocate channel
+ *
+ * - First try to allocate SDCCH.
+ * - If SDCCH is not available, try whatever MS requested, if not SDCCH.
+ * - If there is still no channel available, reject channel request.
+ *
+ * lchan_alloc() possibly tries to allocate larger lchans.
+ *
+ * Note: If the MS requests not TCH/H, we don't know if the phone
+ * supports TCH/H, so we must assign TCH/F or SDCCH.
+ */
+ lchan = lchan_alloc(bts, GSM_LCHAN_SDCCH, 0);
+ if (!lchan && lctype != GSM_LCHAN_SDCCH) {
+ LOGP(DRSL, LOGL_NOTICE, "BTS %d CHAN RQD: no resources for %s "
+ "0x%x, retrying with %s\n",
+ msg->lchan->ts->trx->bts->nr,
+ gsm_lchant_name(GSM_LCHAN_SDCCH), rqd_ref->ra,
+ gsm_lchant_name(lctype));
+ lchan = lchan_alloc(bts, lctype, 0);
+ }
if (!lchan) {
LOGP(DRSL, LOGL_NOTICE, "BTS %d CHAN RQD: no resources for %s 0x%x\n",
msg->lchan->ts->trx->bts->nr, gsm_lchant_name(lctype), rqd_ref->ra);