lchan: Release the lchan more quickly, align with GSM 04.08
* Release all channels with SAPI > 0 with the "local end release"
(as of NOTE 1 of GSM 04.08).
* No need to wait for all SAPIs to be torn down and the normal
REL_IND/REL_CONF will call rsl_handle_release and the channel
should be released.
* Update the documentation
diff --git a/openbsc/src/libbsc/chan_alloc.c b/openbsc/src/libbsc/chan_alloc.c
index 1efe2aa..a8b15d1 100644
--- a/openbsc/src/libbsc/chan_alloc.c
+++ b/openbsc/src/libbsc/chan_alloc.c
@@ -345,8 +345,6 @@
}
lchan->sacch_deact = 0;
- lchan->release_mode = RSL_REL_NORMAL;
-
/* FIXME: ts_free() the timeslot, if we're the last logical
* channel using it */
}
@@ -376,51 +374,22 @@
}
}
-/* release the next allocated SAPI or return 0 */
-static int _lchan_release_next_sapi(struct gsm_lchan *lchan)
-{
- int sapi;
-
- for (sapi = 1; sapi < ARRAY_SIZE(lchan->sapis); ++sapi) {
- uint8_t link_id;
- if (lchan->sapis[sapi] == LCHAN_SAPI_UNUSED)
- continue;
-
- link_id = sapi;
- if (lchan->type == GSM_LCHAN_TCH_F || lchan->type == GSM_LCHAN_TCH_H)
- link_id |= 0x40;
- rsl_release_request(lchan, link_id, RSL_REL_LOCAL_END);
- return 0;
- }
-
- return 1;
-}
-
/* Drive the release process of the lchan */
-static void _lchan_handle_release(struct gsm_lchan *lchan)
+static void _lchan_handle_release(struct gsm_lchan *lchan,
+ int sach_deact, int mode)
{
- /* Ask for SAPI != 0 to be freed first and stop if we need to wait */
- if (_lchan_release_next_sapi(lchan) == 0)
- return;
+ /* Release all SAPIs on the local end and continue */
+ rsl_release_sapis_from(lchan, 1, RSL_REL_LOCAL_END);
- if (lchan->sacch_deact) {
+ /*
+ * Shall we send a RR Release, start T3109 and wait for the
+ * release indication from the BTS or just take it down (e.g.
+ * on assignment requests)
+ */
+ if (sach_deact)
gsm48_send_rr_release(lchan);
- return;
- }
-
- rsl_release_request(lchan, 0, lchan->release_mode);
- rsl_lchan_set_state(lchan, LCHAN_S_REL_REQ);
-}
-
-/* called from abis rsl */
-int rsl_lchan_rll_release(struct gsm_lchan *lchan, uint8_t link_id)
-{
- if (lchan->state != LCHAN_S_REL_REQ)
- return -1;
-
- if ((link_id & 0x7) != 0)
- _lchan_handle_release(lchan);
- return 0;
+ else
+ rsl_release_request(lchan, 0, mode);
}
/* Consider releasing the channel now */
@@ -430,9 +399,7 @@
rsl_lchan_set_state(lchan, LCHAN_S_REL_REQ);
lchan->conn = NULL;
- lchan->release_mode = mode;
- lchan->sacch_deact = sacch_deact;
- _lchan_handle_release(lchan);
+ _lchan_handle_release(lchan, sacch_deact, mode);
return 1;
}