[lchan] Release the channel ones its' usecount drops to zero

Remove the timer handling from the LCHAN and release the
channel ones the use count is dropping to zero.

Change code that was sending/using the lchan after the
release and change the send data method to warn in case
the lchan is used after it has been freed.

2 files changed, 24 insertions, 25 deletions

diff --git a/openbsc/include/openbsc/chan_alloc.h b/openbsc/include/openbsc/chan_alloc.h
index 38855d1ee..ef42fe1c5 100644
--- a/openbsc/include/openbsc/chan_alloc.h
+++ b/openbsc/include/openbsc/chan_alloc.h
@@ -23,6 +23,28 @@
 
 #include "gsm_subscriber.h"
 
+/*
+ * Refcounting for the lchan. If the refcount drops to zero
+ * the channel will send a RSL release request.
+ */
+#define use_lchan(lchan) \
+	do {	lchan->use_count++; \
+		DEBUGP(DCC, "lchan (bts=%d,trx=%d,ts=%d,ch=%d) increases usage to: %d\n", \
+			lchan->ts->trx->bts->nr, lchan->ts->trx->nr, lchan->ts->nr, \
+			lchan->nr, lchan->use_count); \
+	} while(0);
+
+#define put_lchan(lchan) \
+	do { lchan->use_count--; \
+		DEBUGP(DCC, "lchan (bts=%d,trx=%d,ts=%d,ch=%d) decreases usage to: %d\n", \
+			lchan->ts->trx->bts->nr, lchan->ts->trx->nr, lchan->ts->nr, \
+			lchan->nr, lchan->use_count); \
+	    if (lchan->use_count <= 0) \
+		_lchan_release(lchan); \
+	} while(0);
+
+
+
 /* Special allocator for C0 of BTS */
 struct gsm_bts_trx_ts *ts_c0_alloc(struct gsm_bts *bts,
 				   enum gsm_phys_chan_config pchan);
@@ -46,7 +68,7 @@ struct gsm_lchan *lchan_alloc(struct gsm_bts *bts, enum gsm_chan_t type);
 /* Free a logical channel (SDCCH, TCH, ...) */
 void lchan_free(struct gsm_lchan *lchan);
 
-/* Consider releasing the channel */
-int lchan_auto_release(struct gsm_lchan *lchan);
+/* internal.. do not use */
+int _lchan_release(struct gsm_lchan *lchan);
 
 #endif /* _CHAN_ALLOC_H */
diff --git a/openbsc/include/openbsc/gsm_data.h b/openbsc/include/openbsc/gsm_data.h
index 1e66fa482..34bead6ed 100644
--- a/openbsc/include/openbsc/gsm_data.h
+++ b/openbsc/include/openbsc/gsm_data.h
@@ -85,26 +85,6 @@ typedef int gsm_cbfn(unsigned int hooknum,
 		     struct msgb *msg,
 		     void *data, void *param);
 
-/*
- * Use the channel. As side effect the lchannel recycle timer
- * will be started.
- */
-#define LCHAN_RELEASE_TIMEOUT 20, 0
-#define use_lchan(lchan) \
-	do {	lchan->use_count++; \
-		DEBUGP(DCC, "lchan (bts=%d,trx=%d,ts=%d,ch=%d) increases usage to: %d\n", \
-			lchan->ts->trx->bts->nr, lchan->ts->trx->nr, lchan->ts->nr, \
-			lchan->nr, lchan->use_count); \
-		bsc_schedule_timer(&lchan->release_timer, LCHAN_RELEASE_TIMEOUT); } while(0);
-
-#define put_lchan(lchan) \
-	do { lchan->use_count--; \
-		DEBUGP(DCC, "lchan (bts=%d,trx=%d,ts=%d,ch=%d) decreases usage to: %d\n", \
-			lchan->ts->trx->bts->nr, lchan->ts->trx->nr, lchan->ts->nr, \
-			lchan->nr, lchan->use_count); \
-	} while(0);
-
-
 /* communications link with a BTS */
 struct gsm_bts_link {
 	struct gsm_bts *bts;
@@ -203,9 +183,6 @@ struct gsm_lchan {
 	/* To whom we are allocated at the moment */
 	struct gsm_subscriber *subscr;
 
-	/* Timer started to release the channel */
-	struct timer_list release_timer;
-
 	struct timer_list T3101;
 
 	/* Established data link layer services */