wcte43x: Do not reconfigure framer when span lineconfig is not changed.

If dahdi_span_ops.spanconfig is called multiple times in a row (like when
running dahdi_cfg; dahdi_cfg ) the tx signaling bits would go through a spurious
state that some far side devices would respond to.

Now, if the dahdi_span_ops.spanconfig callback is called, and the configuration
matches the existing configuration, we will not touch the framer.

Signed-off-by: Shaun Ruffell <sruffell@digium.com>
Signed-off-by: Russ Meyerriecks <rmeyerriecks@digium.com>

drivers/dahdi/dahdi-base.c

@@ -1811,6 +1811,17 @@ static int start_tone(struct dahdi_chan *chan, int tone)
 	return res;
 }
 
+/**
+ * stop_tone - Stops any tones on a channel.
+ *
+ * Must be called with chan->lock held.
+ *
+ */
+static inline int stop_tone(struct dahdi_chan *chan)
+{
+	return start_tone(chan, -1);
+}
+
 static int set_tone_zone(struct dahdi_chan *chan, int zone)
 {
 	int res = 0;
@@ -1838,6 +1849,9 @@ static int set_tone_zone(struct dahdi_chan *chan, int zone)
 		return -ENODATA;
 
 	spin_lock_irqsave(&chan->lock, flags);
+
+	stop_tone(chan);
+
 	if (chan->curzone) {
 		struct dahdi_zone *zone = chan->curzone;
 		chan->curzone = NULL;

drivers/dahdi/wct4xxp/base.c

@@ -3296,8 +3296,6 @@ static void t4_check_sigbits(struct t4 *wc, int span)
 		dev_notice(&wc->dev->dev, "Checking sigbits on span %d\n",
 				span + 1);
 
-	if (!(ts->span.flags & DAHDI_FLAG_RUNNING))
-		return;
 	if (E1 == ts->linemode) {
 		for (i = 0; i < 15; i++) {
 			a = t4_framer_in(wc, span, 0x71 + i);
@@ -3687,6 +3685,7 @@ static inline void t4_framer_interrupt(struct t4 *wc, int span)
 	struct t4_span *ts = wc->tspans[span];
 	struct dahdi_chan *sigchan;
 	unsigned long flags;
+	bool recheck_sigbits = false;
 
 
 	/* 1st gen cards isn't used interrupts */
@@ -3712,6 +3711,8 @@ static inline void t4_framer_interrupt(struct t4 *wc, int span)
 		ts->span.count.ebit += __t4_framer_in(wc, span, EBCL_T);
 		ts->span.count.be += __t4_framer_in(wc, span, BECL_T);
 		ts->span.count.prbs = __t4_framer_in(wc, span, FRS1_T);
+		if (DAHDI_RXSIG_INITIAL == ts->span.chans[0]->rxhooksig)
+			recheck_sigbits = true;
 	}
 	spin_unlock_irqrestore(&wc->reglock, flags);
  
@@ -3720,7 +3721,7 @@ static inline void t4_framer_interrupt(struct t4 *wc, int span)
  		ts->span.count.errsec += 1;
  	}
  
-	if (isr0)
+	if (isr0 & 0x08 || recheck_sigbits)
 		t4_check_sigbits(wc, span);
 
 	if (E1 == ts->linemode) {

drivers/dahdi/wcte13xp-base.c

@@ -110,6 +110,7 @@ struct t13x {
 	struct vpm450m *vpm;
 	struct mutex lock;
 	struct wcxb xb;
+	u32    lineconfig_fingerprint;
 };
 
 static void te13x_handle_transmit(struct wcxb *xb, void *vfp);
@@ -1675,12 +1676,37 @@ static void t13x_chan_set_sigcap(struct dahdi_span *span, int x)
 	}
 }
 
+static bool t13x_lineconfig_changed(struct t13x *wc,
+				    const struct dahdi_lineconfig *lc)
+{
+	unsigned long flags;
+	bool result;
+	u32 crc = crc32(~0, lc, sizeof(*lc));
+
+	spin_lock_irqsave(&wc->reglock, flags);
+	result = (crc != wc->lineconfig_fingerprint);
+	spin_unlock_irqrestore(&wc->reglock, flags);
+	return result;
+}
+
+static void t13x_save_lineconfig(struct t13x *wc,
+				 const struct dahdi_lineconfig *lc)
+{
+	unsigned long flags;
+	u32 crc = crc32(~0, lc, sizeof(*lc));
+
+	spin_lock_irqsave(&wc->reglock, flags);
+	wc->lineconfig_fingerprint = crc;
+	spin_unlock_irqrestore(&wc->reglock, flags);
+}
+
 static int
 t13x_spanconfig(struct file *file, struct dahdi_span *span,
 		 struct dahdi_lineconfig *lc)
 {
 	struct t13x *wc = container_of(span, struct t13x, span);
 	int i;
+	int res = 0;
 
 	if (file->f_flags & O_NONBLOCK)
 		return -EAGAIN;
@@ -1693,10 +1719,13 @@ t13x_spanconfig(struct file *file, struct dahdi_span *span,
 		t13x_chan_set_sigcap(span, i);
 
 	/* If already running, apply changes immediately */
-	if (test_bit(DAHDI_FLAGBIT_RUNNING, &span->flags))
-		return t13x_startup(file, span);
-
-	return 0;
+	if (test_bit(DAHDI_FLAGBIT_RUNNING, &span->flags) &&
+	    t13x_lineconfig_changed(wc, lc)) {
+		res = t13x_startup(file, span);
+		if (!res)
+			t13x_save_lineconfig(wc, lc);
+	}
+	return res;
 }
 
 /**

drivers/dahdi/wcte43x-base.c

@@ -110,6 +110,7 @@ struct t43x_span {
 	bool debounce;
 	int syncpos;
 	int sync;
+	u32 lineconfig_fingerprint;
 };
 
 struct t43x_clksrc_work {
@@ -2377,6 +2378,30 @@ static void t43x_chan_set_sigcap(struct dahdi_span *span, int x)
 	}
 }
 
+static bool t43x_lineconfig_changed(struct t43x_span *ts,
+				    const struct dahdi_lineconfig *lc)
+{
+	unsigned long flags;
+	bool result;
+	u32 crc = crc32(~0, lc, sizeof(*lc));
+
+	spin_lock_irqsave(&ts->owner->reglock, flags);
+	result = (crc != ts->lineconfig_fingerprint);
+	spin_unlock_irqrestore(&ts->owner->reglock, flags);
+	return result;
+}
+
+static void t43x_save_lineconfig(struct t43x_span *ts,
+				 const struct dahdi_lineconfig *lc)
+{
+	unsigned long flags;
+	u32 crc = crc32(~0, lc, sizeof(*lc));
+
+	spin_lock_irqsave(&ts->owner->reglock, flags);
+	ts->lineconfig_fingerprint = crc;
+	spin_unlock_irqrestore(&ts->owner->reglock, flags);
+}
+
 static int
 t43x_spanconfig(struct file *file, struct dahdi_span *span,
 		 struct dahdi_lineconfig *lc)
@@ -2384,6 +2409,7 @@ t43x_spanconfig(struct file *file, struct dahdi_span *span,
 	struct t43x_span *ts = container_of(span, struct t43x_span, span);
 	struct t43x *wc = ts->owner;
 	int i;
+	int res = 0;
 
 	if (debug)
 		dev_info(&wc->xb.pdev->dev, "%s\n", __func__);
@@ -2420,10 +2446,13 @@ t43x_spanconfig(struct file *file, struct dahdi_span *span,
 		t43x_chan_set_sigcap(span, i);
 
 	/* If already running, apply changes immediately */
-	if (test_bit(DAHDI_FLAGBIT_RUNNING, &span->flags))
-		return t43x_startup(file, span);
-
-	return 0;
+	if (test_bit(DAHDI_FLAGBIT_RUNNING, &span->flags) &&
+	    t43x_lineconfig_changed(ts, lc)) {
+		res = t43x_startup(file, span);
+		if (!res)
+			t43x_save_lineconfig(ts, lc);
+	}
+	return res;
 }
 
 /*