diff --git a/drivers/dahdi/wct4xxp/base.c b/drivers/dahdi/wct4xxp/base.c
index 2b7c4a1..1ed10b1 100644
--- a/drivers/dahdi/wct4xxp/base.c
+++ b/drivers/dahdi/wct4xxp/base.c
@@ -390,7 +390,7 @@ static inline bool is_pcie(const struct t4 *wc)
 
 static inline bool has_e1_span(const struct t4 *wc)
 {
-	return (wc->t1e1) != 0;
+	return (wc->t1e1 > 0);
 }
 
 static inline bool is_octal(const struct t4 *wc)
@@ -1121,6 +1121,7 @@ static int t4_echocan_create(struct dahdi_chan *chan,
 	int channel;
 	const struct dahdi_echocan_ops *ops;
 	const struct dahdi_echocan_features *features;
+	const bool alaw = (chan->span->deflaw == 2);
 
 	if (!vpmsupport || !wc->vpm)
 		return -ENODEV;
@@ -1141,19 +1142,19 @@ static int t4_echocan_create(struct dahdi_chan *chan,
 
 	channel = has_e1_span(wc) ? chan->chanpos : chan->chanpos + 4;
 
-	if (wc->vpm) {
-		if (is_octal(wc))
-			channel = channel << 3;
-		else
-			channel = channel << 2;
-		channel |= chan->span->offset;
-		if (debug & DEBUG_ECHOCAN)
-			dev_notice(&wc->dev->dev, "echocan: Card is %d, "
-				"Channel is %d, Span is %d, offset is %d "
-				"length %d\n", wc->num, chan->chanpos,
-				chan->span->offset, channel, ecp->tap_length);
-		vpm450m_setec(wc->vpm, channel, ecp->tap_length);
+	if (is_octal(wc))
+		channel = channel << 3;
+	else
+		channel = channel << 2;
+	channel |= chan->span->offset;
+	if (debug & DEBUG_ECHOCAN) {
+		dev_notice(&wc->dev->dev,
+			   "echocan: Card is %d, Channel is %d, Span is %d, offset is %d length %d\n",
+			   wc->num, chan->chanpos, chan->span->offset,
+			   channel, ecp->tap_length);
 	}
+	vpm450m_set_alaw_companding(wc->vpm, channel, alaw);
+	vpm450m_setec(wc->vpm, channel, ecp->tap_length);
 	return 0;
 }
 
@@ -1162,23 +1163,23 @@ static void echocan_free(struct dahdi_chan *chan, struct dahdi_echocan_state *ec
 	struct t4 *wc = chan->pvt;
 	int channel;
 
-	memset(ec, 0, sizeof(*ec));
+	if (!wc->vpm)
+		return;
 
+	memset(ec, 0, sizeof(*ec));
 	channel = has_e1_span(wc) ? chan->chanpos : chan->chanpos + 4;
 
-	if (wc->vpm) {
-		if (is_octal(wc))
-			channel = channel << 3;
-		else
-			channel = channel << 2;
-		channel |= chan->span->offset;
-		if (debug & DEBUG_ECHOCAN)
-			dev_notice(&wc->dev->dev, "echocan: Card is %d, "
-				"Channel is %d, Span is %d, offset is %d "
-				"length 0\n", wc->num, chan->chanpos,
-				chan->span->offset, channel);
-		vpm450m_setec(wc->vpm, channel, 0);
+	if (is_octal(wc))
+		channel = channel << 3;
+	else
+		channel = channel << 2;
+	channel |= chan->span->offset;
+	if (debug & DEBUG_ECHOCAN) {
+		dev_notice(&wc->dev->dev,
+			   "echocan: Card is %d, Channel is %d, Span is %d, offset is %d length 0\n",
+			   wc->num, chan->chanpos, chan->span->offset, channel);
 	}
+	vpm450m_setec(wc->vpm, channel, 0);
 }
 #endif
 
@@ -2225,6 +2226,7 @@ static int t4_set_linemode(struct dahdi_span *span, enum spantypes linemode)
 	int res = 0;
 	enum linemode mode;
 	const char *old_name;
+	static DEFINE_MUTEX(linemode_lock);
 
 	dev_dbg(&wc->dev->dev, "Setting '%s' to '%s'\n", span->name,
 		dahdi_spantype2str(linemode));
@@ -2232,22 +2234,27 @@ static int t4_set_linemode(struct dahdi_span *span, enum spantypes linemode)
 	if (span->spantype == linemode)
 		return 0;
 
+	/* Do not allow the t1e1 member to be changed by multiple threads. */
+	mutex_lock(&linemode_lock);
 	old_name = dahdi_spantype2str(span->spantype);
 	switch (linemode) {
 	case SPANTYPE_DIGITAL_T1:
 		dev_info(&wc->dev->dev,
 			 "Changing from %s to T1 line mode.\n", old_name);
 		mode = T1;
+		wc->t1e1 &= ~(1 << span->offset);
 		break;
 	case SPANTYPE_DIGITAL_E1:
 		dev_info(&wc->dev->dev,
 			 "Changing from %s to E1 line mode.\n", old_name);
 		mode = E1;
+		wc->t1e1 |= (1 << span->offset);
 		break;
 	case SPANTYPE_DIGITAL_J1:
 		dev_info(&wc->dev->dev,
 			 "Changing from %s to J1 line mode.\n", old_name);
 		mode = J1;
+		wc->t1e1 &= ~(1 << span->offset);
 		break;
 	default:
 		dev_err(&wc->dev->dev,
@@ -2261,6 +2268,7 @@ static int t4_set_linemode(struct dahdi_span *span, enum spantypes linemode)
 		dahdi_init_span(span);
 	}
 
+	mutex_unlock(&linemode_lock);
 	return res;
 }
 
diff --git a/drivers/dahdi/wct4xxp/vpm450m.c b/drivers/dahdi/wct4xxp/vpm450m.c
index f332f01..45d84fb 100644
--- a/drivers/dahdi/wct4xxp/vpm450m.c
+++ b/drivers/dahdi/wct4xxp/vpm450m.c
@@ -177,6 +177,7 @@ struct vpm450m {
 #define FLAG_DTMF	 (1 << 0)
 #define FLAG_MUTE	 (1 << 1)
 #define FLAG_ECHO	 (1 << 2)
+#define FLAG_ALAW	 (1 << 3)
 
 static unsigned int tones[] = {
 	SOUT_DTMF_1,
@@ -216,6 +217,50 @@ static unsigned int tones[] = {
 	ROUT_G168_1100GB_ON,
 };
 
+void vpm450m_set_alaw_companding(struct vpm450m *vpm450m, int channel,
+					bool alaw)
+{
+	tOCT6100_CHANNEL_MODIFY *modify;
+	UINT32 ulResult;
+	UINT32		law_to_use = (alaw) ? cOCT6100_PCM_A_LAW :
+					      cOCT6100_PCM_U_LAW;
+
+	if (channel >= ARRAY_SIZE(vpm450m->chanflags)) {
+		pr_err("Channel out of bounds in %s\n", __func__);
+		return;
+	}
+	/* If we're already in this companding mode, no need to do anything. */
+	if (alaw == ((vpm450m->chanflags[channel] & FLAG_ALAW) > 0))
+		return;
+
+	modify = kzalloc(sizeof(tOCT6100_CHANNEL_MODIFY), GFP_ATOMIC);
+	if (!modify) {
+		pr_notice("Unable to allocate memory for setec!\n");
+		return;
+	}
+
+	Oct6100ChannelModifyDef(modify);
+	modify->ulChannelHndl =		      vpm450m->aulEchoChanHndl[channel];
+	modify->fTdmConfigModified =		TRUE;
+	modify->TdmConfig.ulSinPcmLaw =		law_to_use;
+	modify->TdmConfig.ulRinPcmLaw =		law_to_use;
+	modify->TdmConfig.ulSoutPcmLaw =	law_to_use;
+	modify->TdmConfig.ulRoutPcmLaw =	law_to_use;
+	ulResult = Oct6100ChannelModify(vpm450m->pApiInstance, modify);
+	if (ulResult != GENERIC_OK) {
+		pr_notice("Failed to apply echo can changes on channel %d %d %08x!\n",
+			  vpm450m->aulEchoChanHndl[channel], channel, ulResult);
+	} else {
+		pr_info("Changed companding on channel %d to %s.\n", channel,
+			(alaw) ? "alaw" : "ulaw");
+		if (alaw)
+			vpm450m->chanflags[channel] |= FLAG_ALAW;
+		else
+			vpm450m->chanflags[channel] &= ~(FLAG_ALAW);
+	}
+	kfree(modify);
+}
+
 static void vpm450m_setecmode(struct vpm450m *vpm450m, int channel, int mode)
 {
 	tOCT6100_CHANNEL_MODIFY *modify;
@@ -248,6 +293,11 @@ void vpm450m_setdtmf(struct vpm450m *vpm450m, int channel, int detect, int mute)
 	tOCT6100_CHANNEL_MODIFY *modify;
 	UINT32 ulResult;
 
+	if (channel >= ARRAY_SIZE(vpm450m->chanflags)) {
+		pr_err("Channel out of bounds in %s\n", __func__);
+		return;
+	}
+
 	modify = kmalloc(sizeof(tOCT6100_CHANNEL_MODIFY), GFP_KERNEL);
 	if (!modify) {
 		printk(KERN_NOTICE "wct4xxp: Unable to allocate memory for setdtmf!\n");
@@ -286,6 +336,11 @@ void vpm450m_setdtmf(struct vpm450m *vpm450m, int channel, int detect, int mute)
 
 void vpm450m_setec(struct vpm450m *vpm450m, int channel, int eclen)
 {
+	if (channel >= ARRAY_SIZE(vpm450m->chanflags)) {
+		pr_err("Channel out of bounds in %s\n", __func__);
+		return;
+	}
+
 	if (eclen) {
 		vpm450m->chanflags[channel] |= FLAG_ECHO;
 		vpm450m_setecmode(vpm450m, channel, cOCT6100_ECHO_OP_MODE_HT_RESET);
@@ -524,10 +579,13 @@ struct vpm450m *init_vpm450m(void *wc, int *isalaw, int numspans, const struct f
 		 	*  therefore, the lower 2 bits tell us which span this 
 			*  timeslot/channel
 		 	*/
-			if (isalaw[x & mask])
+			if (isalaw[x & mask]) {
 				law = cOCT6100_PCM_A_LAW;
-			else
+				vpm450m->chanflags[x] |= FLAG_ALAW;
+			} else {
 				law = cOCT6100_PCM_U_LAW;
+				vpm450m->chanflags[x] &= ~(FLAG_ALAW);
+			}
 			Oct6100ChannelOpenDef(ChannelOpen);
 			ChannelOpen->pulChannelHndl = &vpm450m->aulEchoChanHndl[x];
 			ChannelOpen->ulUserChanId = x;
diff --git a/drivers/dahdi/wct4xxp/vpm450m.h b/drivers/dahdi/wct4xxp/vpm450m.h
index 735a2cc..adf4150 100644
--- a/drivers/dahdi/wct4xxp/vpm450m.h
+++ b/drivers/dahdi/wct4xxp/vpm450m.h
@@ -39,5 +39,7 @@ void vpm450m_setdtmf(struct vpm450m *instance, int channel, int dtmfdetect, int
 int vpm450m_checkirq(struct vpm450m *vpm450m);
 int vpm450m_getdtmf(struct vpm450m *vpm450m, int *channel, int *tone, int *start);
 void release_vpm450m(struct vpm450m *instance);
+void vpm450m_set_alaw_companding(struct vpm450m *vpm450m,
+				 int channel, bool alaw);
 
 #endif