ISDN: Start a unified state machine in isdn_net.c

Currently, the state machine is distributed over multiple functions,
the goal is to convert these to just one function, so it's easier to
grasp what is happening for which state/event combinations.

drivers/isdn/i4l/isdn_common.h

@@ -24,6 +24,10 @@
 #undef  ISDN_DEBUG_NET_DIAL
 #undef  ISDN_DEBUG_NET_ICALL
 
+#define isdn_BUG() \
+do { printk(KERN_WARNING "ISDN Bug at %s:%d", __FILE__, __LINE__); \
+} while(0)
+
 /* Prototypes */
 extern void isdn_MOD_INC_USE_COUNT(void);
 extern void isdn_MOD_DEC_USE_COUNT(void);

drivers/isdn/i4l/isdn_net.c

@@ -54,6 +54,11 @@ enum {
 	ST_12,
 };
 
+/* keep clear of ISDN_CMD_* and ISDN_STAT_* */
+enum {
+	EV_NET_DIAL = 0x200,
+};
+
 /*
  * Outline of new tbusy handling: 
  *
@@ -625,6 +630,7 @@ isdn_net_stat_callback(int idx, isdn_ctrl *c)
 		}
 		break;
 	}
+	return 0;
 }
 
 /* Initiate dialout. Set phone-number-pointer to first number
@@ -745,62 +751,70 @@ do_dialout(isdn_net_local *lp)
 	return 1;
 }
 
-/*
- * Perform dialout for net-interfaces and timeout-handling for
- * D-Channel-up and B-Channel-up Messages.
- * This function is initially called from within isdn_net_start_xmit() or
- * or isdn_net_find_icall() after initializing the dialstate for an
- * interface. If further calls are needed, the function schedules itself
- * for a timer-callback via isdn_timer_function().
- * The dialstate is also affected by incoming status-messages from
- * the ISDN-Channel which are handled in isdn_net_stat_callback() above.
- */
-void
-isdn_net_dial(void)
+/* returns 1 if timer callback is needed */
+static int
+isdn_net_handle_event(isdn_net_local *lp, int pr, void *arg)
 {
-	isdn_net_dev *p = dev->netdev;
-	int anymore = 0;
+	isdn_net_dev *p = lp->netdev;
 	isdn_ctrl cmd;
 
-	for (p = dev->netdev; p; p = p->next) {
-		isdn_net_local *lp = p->local;
-
 #ifdef ISDN_DEBUG_NET_DIAL
-		if (lp->dialstate)
-			printk(KERN_DEBUG "%s: dialstate=%d\n", lp->name, lp->dialstate);
+	printk(KERN_DEBUG "%s: dialstate=%d\n", lp->name, lp->dialstate);
 #endif
-		switch (lp->dialstate) {
-		case ST_0:
-			/* Nothing to do for this interface */
-			break;
-		case ST_1:
-			anymore = init_dialout(lp);
-			/* Fall through */
-		case ST_2:
+
+	switch (lp->dialstate) {
+	case ST_0:
+		break;
+	case ST_1:
+		switch (pr) {
+		case EV_NET_DIAL:
+			if (init_dialout(lp) == 0)
+				return 0;
+			lp->dialstate = ST_2;
+			goto st_2_net_dial;
+		}
+		break;
+	case ST_2:
+		switch (pr) {
+		case EV_NET_DIAL:
+		st_2_net_dial:
 			lp->dialretry = 0;
-			anymore = 1;
 			lp->dialstate = ST_3;
-			/* Fall through */
-		case ST_3:
-			anymore = do_dialout(lp);
-			break;
-		case ST_4:
+			goto st_3_net_dial;
+		}
+		break;
+	case ST_3:
+		switch (pr) {
+		case EV_NET_DIAL:
+		st_3_net_dial:
+			return do_dialout(lp);
+		}
+		break;
+	case ST_4:
+		switch (pr) {
+		case EV_NET_DIAL:
 			/* Wait for D-Channel-connect.
 			 * If timeout, switch back to state 3.
 			 * Dialmax-handling moved to state 3.
 			 */
 			if (lp->dtimer++ > ISDN_TIMER_DTIMEOUT10)
-					lp->dialstate = ST_3;
-			anymore = 1;
-			break;
-		case ST_5:
+				lp->dialstate = ST_3;
+			return 1;
+		}
+		break;
+	case ST_5:
+		switch (pr) {
+		case EV_NET_DIAL:
 			/* Got D-Channel-Connect, send B-Channel-request */
-			anymore = 1;
 			lp->dtimer = 0;
 			lp->dialstate = ST_6;
 			isdn_slot_command(lp->isdn_slot, ISDN_CMD_ACCEPTB, &cmd);
-			break;
-		case ST_6:
+			return 1;
+		}
+		break;
+	case ST_6:
+		switch (pr) {
+		case EV_NET_DIAL:
 			/* Wait for B- or D-Channel-connect. If timeout,
 			 * switch back to state 3.
 			 */
@@ -809,9 +823,12 @@ isdn_net_dial(void)
 #endif
 			if (lp->dtimer++ > ISDN_TIMER_DTIMEOUT10)
 				lp->dialstate = ST_3;
-			anymore = 1;
-			break;
-		case ST_7:
+			return 1;
+		}
+		break;
+	case ST_7:
+		switch (pr) {
+		case EV_NET_DIAL:
 			/* Got incoming Call, setup L2 and L3 protocols,
 			 * then wait for D-Channel-connect
 			 */
@@ -822,38 +839,52 @@ isdn_net_dial(void)
 			isdn_slot_command(lp->isdn_slot, ISDN_CMD_SETL2, &cmd);
 			cmd.arg = lp->l3_proto << 8;
 			isdn_slot_command(lp->isdn_slot, ISDN_CMD_SETL3, &cmd);
-			if (lp->dtimer++ > ISDN_TIMER_DTIMEOUT15)
+			if (lp->dtimer++ > ISDN_TIMER_DTIMEOUT15) {
 				isdn_net_hangup(&p->dev);
-			else {
-				anymore = 1;
+			} else {
 				lp->dialstate = ST_8;
+				return 1;
 			}
 			break;
-		case ST_9:
+		}
+		break;
+	case ST_9:
+		switch (pr) {
+		case EV_NET_DIAL:
 			/* Got incoming D-Channel-Connect, send B-Channel-request */
 			isdn_slot_command(lp->isdn_slot, ISDN_CMD_ACCEPTB, &cmd);
-			anymore = 1;
 			lp->dtimer = 0;
 			lp->dialstate = ST_10;
-			break;
-		case ST_8:
-		case ST_10:
-			/*  Wait for B- or D-channel-connect */
+			return 1;
+		}
+		break;
+	case ST_8:
+	case ST_10:
+		switch (pr) {
+		case EV_NET_DIAL:
+		/*  Wait for B- or D-channel-connect */
 #ifdef ISDN_DEBUG_NET_DIAL
 			printk(KERN_DEBUG "dialtimer4: %d\n", lp->dtimer);
 #endif
 			if (lp->dtimer++ > ISDN_TIMER_DTIMEOUT10)
 				isdn_net_hangup(&p->dev);
 			else
-				anymore = 1;
+				return 1;
 			break;
-		case ST_11:
+		}
+		break;
+	case ST_11:
+		switch (pr) {
+		case EV_NET_DIAL:
 			/* Callback Delay */
 			if (lp->dtimer++ > lp->cbdelay)
 				lp->dialstate = ST_1;
-			anymore = 1;
-			break;
-		case ST_12:
+			return 1;
+		}
+		break;
+	case ST_12:
+		switch (pr) {
+		case EV_NET_DIAL:
 			/* Remote does callback. Hangup after cbdelay, then wait for incoming
 			 * call (in state 4).
 			 */
@@ -864,12 +895,40 @@ isdn_net_dial(void)
 				isdn_slot_command(lp->isdn_slot, ISDN_CMD_HANGUP, &cmd);
 				isdn_slot_all_eaz(lp->isdn_slot);
 			}
-			anymore = 1;
-			break;
-		default:
-			printk(KERN_WARNING "isdn_net: Illegal dialstate %d for device %s\n",
-			       lp->dialstate, lp->name);
+			return 1;
 		}
+		break;
+	default:
+		isdn_BUG();
+		break;
+	}
+	return 0;
+}
+
+/*
+ * Perform dialout for net-interfaces and timeout-handling for
+ * D-Channel-up and B-Channel-up Messages.
+ * This function is initially called from within isdn_net_start_xmit() or
+ * or isdn_net_find_icall() after initializing the dialstate for an
+ * interface. If further calls are needed, the function schedules itself
+ * for a timer-callback via isdn_timer_function().
+ * The dialstate is also affected by incoming status-messages from
+ * the ISDN-Channel which are handled in isdn_net_stat_callback() above.
+ */
+void
+isdn_net_dial(void)
+{
+	int anymore = 0;
+	isdn_net_dev *p = dev->netdev;
+
+	for (p = dev->netdev; p; p = p->next) {
+		isdn_net_local *lp = p->local;
+		
+		if (lp->dialstate == ST_0)
+			continue;
+
+		if (isdn_net_handle_event(lp, EV_NET_DIAL, NULL))
+			anymore = 1;
 	}
 	isdn_timer_ctrl(ISDN_TIMER_NETDIAL, anymore);
 }