[alloc] Assign a TCH for LU when all SDCCHs are occupied.

When the cell becomes visible we will be bombed with location
updating requests and to reduce the load on the network we should
assign as many channels for it as possible. During load peek it
is even more important than to have a spare voice channel and in
general the LU procedure is pretty fast.

1 files changed, 15 insertions, 1 deletions

diff --git a/openbsc/src/chan_alloc.c b/openbsc/src/chan_alloc.c
index 1fb0a4f1e..06c75102a 100644
--- a/openbsc/src/chan_alloc.c
+++ b/openbsc/src/chan_alloc.c
@@ -223,7 +223,8 @@ _lc_find_bts(struct gsm_bts *bts, enum gsm_phys_chan_config pchan)
 }
 
 /* Allocate a logical channel */
-struct gsm_lchan *lchan_alloc(struct gsm_bts *bts, enum gsm_chan_t type)
+struct gsm_lchan *lchan_alloc(struct gsm_bts *bts, enum gsm_chan_t type,
+			      int allow_bigger)
 {
 	struct gsm_lchan *lchan = NULL;
 	enum gsm_phys_chan_config first, second;
@@ -241,6 +242,19 @@ struct gsm_lchan *lchan_alloc(struct gsm_bts *bts, enum gsm_chan_t type)
 		lchan = _lc_find_bts(bts, first);
 		if (lchan == NULL)
 			lchan = _lc_find_bts(bts, second);
+
+		/* allow to assign bigger channels */
+		if (allow_bigger) {
+			if (lchan == NULL) {
+				lchan = _lc_find_bts(bts, GSM_PCHAN_TCH_H);
+				type = GSM_LCHAN_TCH_H;
+			}
+
+			if (lchan == NULL) {
+				lchan = _lc_find_bts(bts, GSM_PCHAN_TCH_F);
+				type = GSM_LCHAN_TCH_F;
+			}
+		}
 		break;
 	case GSM_LCHAN_TCH_F:
 		lchan = _lc_find_bts(bts, GSM_PCHAN_TCH_F);