isdn/gigaset: unify function return values

Various functions in the Gigaset driver were using different
conventions for the meaning of their int return values.
Align them to the usual negative error numbers convention.

Inspired-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>

10 files changed, 87 insertions, 81 deletions

diff --git a/drivers/isdn/gigaset/bas-gigaset.c b/drivers/isdn/gigaset/bas-gigaset.c
index d651523..3b9278b 100644
--- a/drivers/isdn/gigaset/bas-gigaset.c
+++ b/drivers/isdn/gigaset/bas-gigaset.c
@@ -2077,16 +2077,14 @@ static int gigaset_brkchars(struct cardstate *cs, const unsigned char buf[6])
 /* Free hardware dependent part of the B channel structure
  * parameter:
  *	bcs	B channel structure
- * return value:
- *	!=0 on success
  */
-static int gigaset_freebcshw(struct bc_state *bcs)
+static void gigaset_freebcshw(struct bc_state *bcs)
 {
 	struct bas_bc_state *ubc = bcs->hw.bas;
 	int i;
 
 	if (!ubc)
-		return 0;
+		return;
 
 	/* kill URBs and tasklets before freeing - better safe than sorry */
 	ubc->running = 0;
@@ -2104,14 +2102,13 @@ static int gigaset_freebcshw(struct bc_state *bcs)
 	kfree(ubc->isooutbuf);
 	kfree(ubc);
 	bcs->hw.bas = NULL;
-	return 1;
 }
 
 /* Initialize hardware dependent part of the B channel structure
  * parameter:
  *	bcs	B channel structure
  * return value:
- *	!=0 on success
+ *	0 on success, error code < 0 on failure
  */
 static int gigaset_initbcshw(struct bc_state *bcs)
 {
@@ -2121,7 +2118,7 @@ static int gigaset_initbcshw(struct bc_state *bcs)
 	bcs->hw.bas = ubc = kmalloc(sizeof(struct bas_bc_state), GFP_KERNEL);
 	if (!ubc) {
 		pr_err("out of memory\n");
-		return 0;
+		return -ENOMEM;
 	}
 
 	ubc->running = 0;
@@ -2138,7 +2135,7 @@ static int gigaset_initbcshw(struct bc_state *bcs)
 		pr_err("out of memory\n");
 		kfree(ubc);
 		bcs->hw.bas = NULL;
-		return 0;
+		return -ENOMEM;
 	}
 	tasklet_init(&ubc->sent_tasklet,
 		     write_iso_tasklet, (unsigned long) bcs);
@@ -2163,7 +2160,7 @@ static int gigaset_initbcshw(struct bc_state *bcs)
 	ubc->stolen0s = 0;
 	tasklet_init(&ubc->rcvd_tasklet,
 		     read_iso_tasklet, (unsigned long) bcs);
-	return 1;
+	return 0;
 }
 
 static void gigaset_reinitbcshw(struct bc_state *bcs)
@@ -2186,6 +2183,12 @@ static void gigaset_freecshw(struct cardstate *cs)
 	cs->hw.bas = NULL;
 }
 
+/* Initialize hardware dependent part of the cardstate structure
+ * parameter:
+ *	cs	cardstate structure
+ * return value:
+ *	0 on success, error code < 0 on failure
+ */
 static int gigaset_initcshw(struct cardstate *cs)
 {
 	struct bas_cardstate *ucs;
@@ -2193,13 +2196,13 @@ static int gigaset_initcshw(struct cardstate *cs)
 	cs->hw.bas = ucs = kmalloc(sizeof *ucs, GFP_KERNEL);
 	if (!ucs) {
 		pr_err("out of memory\n");
-		return 0;
+		return -ENOMEM;
 	}
 	ucs->int_in_buf = kmalloc(IP_MSGSIZE, GFP_KERNEL);
 	if (!ucs->int_in_buf) {
 		kfree(ucs);
 		pr_err("out of memory\n");
-		return 0;
+		return -ENOMEM;
 	}
 
 	ucs->urb_cmd_in = NULL;
@@ -2218,7 +2221,7 @@ static int gigaset_initcshw(struct cardstate *cs)
 	init_waitqueue_head(&ucs->waitqueue);
 	INIT_WORK(&ucs->int_in_wq, int_in_work);
 
-	return 1;
+	return 0;
 }
 
 /* freeurbs
@@ -2378,18 +2381,20 @@ static int gigaset_probe(struct usb_interface *interface,
 	/* save address of controller structure */
 	usb_set_intfdata(interface, cs);
 
-	if (!gigaset_start(cs))
+	rc = gigaset_start(cs);
+	if (rc < 0)
 		goto error;
 
 	return 0;
 
 allocerr:
 	dev_err(cs->dev, "could not allocate URBs\n");
+	rc = -ENOMEM;
 error:
 	freeurbs(cs);
 	usb_set_intfdata(interface, NULL);
 	gigaset_freecs(cs);
-	return -ENODEV;
+	return rc;
 }
 
 /* gigaset_disconnect
diff --git a/drivers/isdn/gigaset/capi.c b/drivers/isdn/gigaset/capi.c
index 86cee65..27e4a3e 100644
--- a/drivers/isdn/gigaset/capi.c
+++ b/drivers/isdn/gigaset/capi.c
@@ -2346,7 +2346,7 @@ static const struct file_operations gigaset_proc_fops = {
  * @cs:		device descriptor structure.
  * @isdnid:	device name.
  *
- * Return value: 1 for success, 0 for failure
+ * Return value: 0 on success, error code < 0 on failure
  */
 int gigaset_isdn_regdev(struct cardstate *cs, const char *isdnid)
 {
@@ -2356,7 +2356,7 @@ int gigaset_isdn_regdev(struct cardstate *cs, const char *isdnid)
 	iif = kmalloc(sizeof(*iif), GFP_KERNEL);
 	if (!iif) {
 		pr_err("%s: out of memory\n", __func__);
-		return 0;
+		return -ENOMEM;
 	}
 
 	/* prepare controller structure */
@@ -2380,12 +2380,12 @@ int gigaset_isdn_regdev(struct cardstate *cs, const char *isdnid)
 	if (rc) {
 		pr_err("attach_capi_ctr failed (%d)\n", rc);
 		kfree(iif);
-		return 0;
+		return rc;
 	}
 
 	cs->iif = iif;
 	cs->hw_hdr_len = CAPI_DATA_B3_REQ_LEN;
-	return 1;
+	return 0;
 }
 
 /**
diff --git a/drivers/isdn/gigaset/common.c b/drivers/isdn/gigaset/common.c
index 6c306d4..aa41485 100644
--- a/drivers/isdn/gigaset/common.c
+++ b/drivers/isdn/gigaset/common.c
@@ -194,13 +194,13 @@ int gigaset_get_channel(struct bc_state *bcs)
 		gig_dbg(DEBUG_CHANNEL, "could not allocate channel %d",
 			bcs->channel);
 		spin_unlock_irqrestore(&bcs->cs->lock, flags);
-		return 0;
+		return -EBUSY;
 	}
 	++bcs->use_count;
 	bcs->busy = 1;
 	gig_dbg(DEBUG_CHANNEL, "allocated channel %d", bcs->channel);
 	spin_unlock_irqrestore(&bcs->cs->lock, flags);
-	return 1;
+	return 0;
 }
 
 struct bc_state *gigaset_get_free_channel(struct cardstate *cs)
@@ -258,7 +258,7 @@ int gigaset_get_channels(struct cardstate *cs)
 			spin_unlock_irqrestore(&cs->lock, flags);
 			gig_dbg(DEBUG_CHANNEL,
 				"could not allocate all channels");
-			return 0;
+			return -EBUSY;
 		}
 	for (i = 0; i < cs->channels; ++i)
 		++cs->bcs[i].use_count;
@@ -266,7 +266,7 @@ int gigaset_get_channels(struct cardstate *cs)
 
 	gig_dbg(DEBUG_CHANNEL, "allocated all channels");
 
-	return 1;
+	return 0;
 }
 
 void gigaset_free_channels(struct cardstate *cs)
@@ -388,8 +388,7 @@ static void gigaset_freebcs(struct bc_state *bcs)
 	int i;
 
 	gig_dbg(DEBUG_INIT, "freeing bcs[%d]->hw", bcs->channel);
-	if (!bcs->cs->ops->freebcshw(bcs))
-		gig_dbg(DEBUG_INIT, "failed");
+	bcs->cs->ops->freebcshw(bcs);
 
 	gig_dbg(DEBUG_INIT, "clearing bcs[%d]->at_state", bcs->channel);
 	clear_at_state(&bcs->at_state);
@@ -566,6 +565,8 @@ static void gigaset_inbuf_init(struct inbuf_t *inbuf, struct cardstate *cs)
  * @inbuf:	buffer structure.
  * @src:	received data.
  * @numbytes:	number of bytes received.
+ *
+ * Return value: !=0 if some data was appended
  */
 int gigaset_fill_inbuf(struct inbuf_t *inbuf, const unsigned char *src,
 		       unsigned numbytes)
@@ -609,8 +610,8 @@ int gigaset_fill_inbuf(struct inbuf_t *inbuf, const unsigned char *src,
 EXPORT_SYMBOL_GPL(gigaset_fill_inbuf);
 
 /* Initialize the b-channel structure */
-static struct bc_state *gigaset_initbcs(struct bc_state *bcs,
-					struct cardstate *cs, int channel)
+static int gigaset_initbcs(struct bc_state *bcs, struct cardstate *cs,
+			   int channel)
 {
 	int i;
 
@@ -649,11 +650,7 @@ static struct bc_state *gigaset_initbcs(struct bc_state *bcs,
 	bcs->apconnstate = 0;
 
 	gig_dbg(DEBUG_INIT, "  setting up bcs[%d]->hw", channel);
-	if (cs->ops->initbcshw(bcs))
-		return bcs;
-
-	gig_dbg(DEBUG_INIT, "  failed");
-	return NULL;
+	return cs->ops->initbcshw(bcs);
 }
 
 /**
@@ -752,7 +749,7 @@ struct cardstate *gigaset_initcs(struct gigaset_driver *drv, int channels,
 	cs->cmdbytes = 0;
 
 	gig_dbg(DEBUG_INIT, "setting up iif");
-	if (!gigaset_isdn_regdev(cs, modulename)) {
+	if (gigaset_isdn_regdev(cs, modulename) < 0) {
 		pr_err("error registering ISDN device\n");
 		goto error;
 	}
@@ -760,7 +757,7 @@ struct cardstate *gigaset_initcs(struct gigaset_driver *drv, int channels,
 	make_valid(cs, VALID_ID);
 	++cs->cs_init;
 	gig_dbg(DEBUG_INIT, "setting up hw");
-	if (!cs->ops->initcshw(cs))
+	if (cs->ops->initcshw(cs) < 0)
 		goto error;
 
 	++cs->cs_init;
@@ -774,7 +771,7 @@ struct cardstate *gigaset_initcs(struct gigaset_driver *drv, int channels,
 	/* set up channel data structures */
 	for (i = 0; i < channels; ++i) {
 		gig_dbg(DEBUG_INIT, "setting up bcs[%d]", i);
-		if (!gigaset_initbcs(cs->bcs + i, cs, i)) {
+		if (gigaset_initbcs(cs->bcs + i, cs, i) < 0) {
 			pr_err("could not allocate channel %d data\n", i);
 			goto error;
 		}
@@ -869,7 +866,7 @@ static void cleanup_cs(struct cardstate *cs)
 
 	for (i = 0; i < cs->channels; ++i) {
 		gigaset_freebcs(cs->bcs + i);
-		if (!gigaset_initbcs(cs->bcs + i, cs, i))
+		if (gigaset_initbcs(cs->bcs + i, cs, i) < 0)
 			pr_err("could not allocate channel %d data\n", i);
 	}
 
@@ -890,14 +887,14 @@ static void cleanup_cs(struct cardstate *cs)
  * waiting for completion of the initialization.
  *
  * Return value:
- *	1 - success, 0 - error
+ *	0 on success, error code < 0 on failure
  */
 int gigaset_start(struct cardstate *cs)
 {
 	unsigned long flags;
 
 	if (mutex_lock_interruptible(&cs->mutex))
-		return 0;
+		return -EBUSY;
 
 	spin_lock_irqsave(&cs->lock, flags);
 	cs->connected = 1;
@@ -921,11 +918,11 @@ int gigaset_start(struct cardstate *cs)
 	wait_event(cs->waitqueue, !cs->waiting);
 
 	mutex_unlock(&cs->mutex);
-	return 1;
+	return 0;
 
 error:
 	mutex_unlock(&cs->mutex);
-	return 0;
+	return -ENOMEM;
 }
 EXPORT_SYMBOL_GPL(gigaset_start);
 
@@ -937,7 +934,7 @@ EXPORT_SYMBOL_GPL(gigaset_start);
  * waiting for completion of the shutdown.
  *
  * Return value:
- *	0 - success, -1 - error (no device associated)
+ *	0 - success, -ENODEV - error (no device associated)
  */
 int gigaset_shutdown(struct cardstate *cs)
 {
@@ -945,7 +942,7 @@ int gigaset_shutdown(struct cardstate *cs)
 
 	if (!(cs->flags & VALID_MINOR)) {
 		mutex_unlock(&cs->mutex);
-		return -1;
+		return -ENODEV;
 	}
 
 	cs->waiting = 1;
diff --git a/drivers/isdn/gigaset/dummyll.c b/drivers/isdn/gigaset/dummyll.c
index 19b1c77..570c2d5 100644
--- a/drivers/isdn/gigaset/dummyll.c
+++ b/drivers/isdn/gigaset/dummyll.c
@@ -60,7 +60,7 @@ void gigaset_isdn_stop(struct cardstate *cs)
 
 int gigaset_isdn_regdev(struct cardstate *cs, const char *isdnid)
 {
-	return 1;
+	return 0;
 }
 
 void gigaset_isdn_unregdev(struct cardstate *cs)
diff --git a/drivers/isdn/gigaset/ev-layer.c b/drivers/isdn/gigaset/ev-layer.c
index 8391e09..2e6963d 100644
--- a/drivers/isdn/gigaset/ev-layer.c
+++ b/drivers/isdn/gigaset/ev-layer.c
@@ -658,7 +658,7 @@ static inline struct at_state_t *get_free_channel(struct cardstate *cs,
 	struct at_state_t *ret;
 
 	for (i = 0; i < cs->channels; ++i)
-		if (gigaset_get_channel(cs->bcs + i)) {
+		if (gigaset_get_channel(cs->bcs + i) >= 0) {
 			ret = &cs->bcs[i].at_state;
 			ret->cid = cid;
 			return ret;
@@ -923,18 +923,18 @@ static void do_stop(struct cardstate *cs)
  * channel >= 0: getting cid for the channel failed
  * channel < 0:  entering cid mode failed
  *
- * returns 0 on failure
+ * returns 0 on success, <0 on failure
  */
 static int reinit_and_retry(struct cardstate *cs, int channel)
 {
 	int i;
 
 	if (--cs->retry_count <= 0)
-		return 0;
+		return -EFAULT;
 
 	for (i = 0; i < cs->channels; ++i)
 		if (cs->bcs[i].at_state.cid > 0)
-			return 0;
+			return -EBUSY;
 
 	if (channel < 0)
 		dev_warn(cs->dev,
@@ -945,7 +945,7 @@ static int reinit_and_retry(struct cardstate *cs, int channel)
 		cs->bcs[channel].at_state.pending_commands |= PC_CID;
 	}
 	schedule_init(cs, MS_INIT);
-	return 1;
+	return 0;
 }
 
 static int at_state_invalid(struct cardstate *cs,
@@ -1016,7 +1016,7 @@ static int do_lock(struct cardstate *cs)
 			if (cs->bcs[i].at_state.pending_commands)
 				return -EBUSY;
 
-		if (!gigaset_get_channels(cs))
+		if (gigaset_get_channels(cs) < 0)
 			return -EBUSY;
 
 		break;
@@ -1125,7 +1125,7 @@ static void do_action(int action, struct cardstate *cs,
 			init_failed(cs, M_UNKNOWN);
 			break;
 		}
-		if (!reinit_and_retry(cs, -1))
+		if (reinit_and_retry(cs, -1) < 0)
 			schedule_init(cs, MS_RECOVER);
 		break;
 	case ACT_FAILUMODE:
@@ -1268,7 +1268,7 @@ static void do_action(int action, struct cardstate *cs,
 	case ACT_FAILCID:
 		cs->cur_at_seq = SEQ_NONE;
 		channel = cs->curchannel;
-		if (!reinit_and_retry(cs, channel)) {
+		if (reinit_and_retry(cs, channel) < 0) {
 			dev_warn(cs->dev,
 				 "Could not get a call ID. Cannot dial.\n");
 			at_state2 = &cs->bcs[channel].at_state;
diff --git a/drivers/isdn/gigaset/gigaset.h b/drivers/isdn/gigaset/gigaset.h
index eae7351..8e2fc8f 100644
--- a/drivers/isdn/gigaset/gigaset.h
+++ b/drivers/isdn/gigaset/gigaset.h
@@ -583,7 +583,7 @@ struct gigaset_ops {
 	int (*initbcshw)(struct bc_state *bcs);
 
 	/* Called by gigaset_freecs() for freeing bcs->hw.xxx */
-	int (*freebcshw)(struct bc_state *bcs);
+	void (*freebcshw)(struct bc_state *bcs);
 
 	/* Called by gigaset_bchannel_down() for resetting bcs->hw.xxx */
 	void (*reinitbcshw)(struct bc_state *bcs);
diff --git a/drivers/isdn/gigaset/i4l.c b/drivers/isdn/gigaset/i4l.c
index 0f13eb1..2d753290 100644
--- a/drivers/isdn/gigaset/i4l.c
+++ b/drivers/isdn/gigaset/i4l.c
@@ -229,7 +229,7 @@ static int command_from_LL(isdn_ctrl *cntrl)
 			return -EINVAL;
 		}
 		bcs = cs->bcs + ch;
-		if (!gigaset_get_channel(bcs)) {
+		if (gigaset_get_channel(bcs) < 0) {
 			dev_err(cs->dev, "ISDN_CMD_DIAL: channel not free\n");
 			return -EBUSY;
 		}
@@ -618,7 +618,7 @@ void gigaset_isdn_stop(struct cardstate *cs)
  * @cs:		device descriptor structure.
  * @isdnid:	device name.
  *
- * Return value: 1 for success, 0 for failure
+ * Return value: 0 on success, error code < 0 on failure
  */
 int gigaset_isdn_regdev(struct cardstate *cs, const char *isdnid)
 {
@@ -627,14 +627,14 @@ int gigaset_isdn_regdev(struct cardstate *cs, const char *isdnid)
 	iif = kmalloc(sizeof *iif, GFP_KERNEL);
 	if (!iif) {
 		pr_err("out of memory\n");
-		return 0;
+		return -ENOMEM;
 	}
 
 	if (snprintf(iif->id, sizeof iif->id, "%s_%u", isdnid, cs->minor_index)
 	    >= sizeof iif->id) {
 		pr_err("ID too long: %s\n", isdnid);
 		kfree(iif);
-		return 0;
+		return -EINVAL;
 	}
 
 	iif->owner = THIS_MODULE;
@@ -656,13 +656,13 @@ int gigaset_isdn_regdev(struct cardstate *cs, const char *isdnid)
 	if (!register_isdn(iif)) {
 		pr_err("register_isdn failed\n");
 		kfree(iif);
-		return 0;
+		return -EINVAL;
 	}
 
 	cs->iif = iif;
 	cs->myid = iif->channels;		/* Set my device id */
 	cs->hw_hdr_len = HW_HDR_LEN;
-	return 1;
+	return 0;
 }
 
 /**
diff --git a/drivers/isdn/gigaset/isocdata.c b/drivers/isdn/gigaset/isocdata.c
index a351c16..bc29f1d 100644
--- a/drivers/isdn/gigaset/isocdata.c
+++ b/drivers/isdn/gigaset/isocdata.c
@@ -56,7 +56,7 @@ static inline int isowbuf_freebytes(struct isowbuf_t *iwb)
 
 /* start writing
  * acquire the write semaphore
- * return true if acquired, false if busy
+ * return 0 if acquired, <0 if busy
  */
 static inline int isowbuf_startwrite(struct isowbuf_t *iwb)
 {
@@ -64,12 +64,12 @@ static inline int isowbuf_startwrite(struct isowbuf_t *iwb)
 		atomic_inc(&iwb->writesem);
 		gig_dbg(DEBUG_ISO, "%s: couldn't acquire iso write semaphore",
 			__func__);
-		return 0;
+		return -EBUSY;
 	}
 	gig_dbg(DEBUG_ISO,
 		"%s: acquired iso write semaphore, data[write]=%02x, nbits=%d",
 		__func__, iwb->data[iwb->write], iwb->wbits);
-	return 1;
+	return 0;
 }
 
 /* finish writing
@@ -158,7 +158,7 @@ int gigaset_isowbuf_getbytes(struct isowbuf_t *iwb, int size)
 		/* no wraparound in valid data */
 		if (limit >= write) {
 			/* append idle frame */
-			if (!isowbuf_startwrite(iwb))
+			if (isowbuf_startwrite(iwb) < 0)
 				return -EBUSY;
 			/* write position could have changed */
 			write = iwb->write;
@@ -403,7 +403,7 @@ static inline int hdlc_buildframe(struct isowbuf_t *iwb,
 	unsigned char c;
 
 	if (isowbuf_freebytes(iwb) < count + count / 5 + 6 ||
-	    !isowbuf_startwrite(iwb)) {
+	    isowbuf_startwrite(iwb) < 0) {
 		gig_dbg(DEBUG_ISO, "%s: %d bytes free -> -EAGAIN",
 			__func__, isowbuf_freebytes(iwb));
 		return -EAGAIN;
@@ -457,7 +457,7 @@ static inline int trans_buildframe(struct isowbuf_t *iwb,
 		return iwb->write;
 
 	if (isowbuf_freebytes(iwb) < count ||
-	    !isowbuf_startwrite(iwb)) {
+	    isowbuf_startwrite(iwb) < 0) {
 		gig_dbg(DEBUG_ISO, "can't put %d bytes", count);
 		return -EAGAIN;
 	}
diff --git a/drivers/isdn/gigaset/ser-gigaset.c b/drivers/isdn/gigaset/ser-gigaset.c
index 6f3fd4c..8c91fd5eb 100644
--- a/drivers/isdn/gigaset/ser-gigaset.c
+++ b/drivers/isdn/gigaset/ser-gigaset.c
@@ -340,17 +340,16 @@ static int gigaset_initbcshw(struct bc_state *bcs)
 {
 	/* unused */
 	bcs->hw.ser = NULL;
-	return 1;
+	return 0;
 }
 
 /*
  * Free B channel structure
  * Called by "gigaset_freebcs" in common.c
  */
-static int gigaset_freebcshw(struct bc_state *bcs)
+static void gigaset_freebcshw(struct bc_state *bcs)
 {
 	/* unused */
-	return 1;
 }
 
 /*
@@ -398,7 +397,7 @@ static int gigaset_initcshw(struct cardstate *cs)
 	scs = kzalloc(sizeof(struct ser_cardstate), GFP_KERNEL);
 	if (!scs) {
 		pr_err("out of memory\n");
-		return 0;
+		return -ENOMEM;
 	}
 	cs->hw.ser = scs;
 
@@ -410,13 +409,13 @@ static int gigaset_initcshw(struct cardstate *cs)
 		pr_err("error %d registering platform device\n", rc);
 		kfree(cs->hw.ser);
 		cs->hw.ser = NULL;
-		return 0;
+		return rc;
 	}
 	dev_set_drvdata(&cs->hw.ser->dev.dev, cs);
 
 	tasklet_init(&cs->write_tasklet,
 		     gigaset_modem_fill, (unsigned long) cs);
-	return 1;
+	return 0;
 }
 
 /*
@@ -503,6 +502,7 @@ static int
 gigaset_tty_open(struct tty_struct *tty)
 {
 	struct cardstate *cs;
+	int rc;
 
 	gig_dbg(DEBUG_INIT, "Starting HLL for Gigaset M101");
 
@@ -515,8 +515,10 @@ gigaset_tty_open(struct tty_struct *tty)
 
 	/* allocate memory for our device state and initialize it */
 	cs = gigaset_initcs(driver, 1, 1, 0, cidmode, GIGASET_MODULENAME);
-	if (!cs)
+	if (!cs) {
+		rc = -ENODEV;
 		goto error;
+	}
 
 	cs->dev = &cs->hw.ser->dev.dev;
 	cs->hw.ser->tty = tty;
@@ -530,7 +532,8 @@ gigaset_tty_open(struct tty_struct *tty)
 	 */
 	if (startmode == SM_LOCKED)
 		cs->mstate = MS_LOCKED;
-	if (!gigaset_start(cs)) {
+	rc = gigaset_start(cs);
+	if (rc < 0) {
 		tasklet_kill(&cs->write_tasklet);
 		goto error;
 	}
@@ -542,7 +545,7 @@ error:
 	gig_dbg(DEBUG_INIT, "Startup of HLL failed");
 	tty->disc_data = NULL;
 	gigaset_freecs(cs);
-	return -ENODEV;
+	return rc;
 }
 
 /*
diff --git a/drivers/isdn/gigaset/usb-gigaset.c b/drivers/isdn/gigaset/usb-gigaset.c
index 049da67..bb12d80 100644
--- a/drivers/isdn/gigaset/usb-gigaset.c
+++ b/drivers/isdn/gigaset/usb-gigaset.c
@@ -549,10 +549,9 @@ static int gigaset_brkchars(struct cardstate *cs, const unsigned char buf[6])
 			       0, 0, &buf, 6, 2000);
 }
 
-static int gigaset_freebcshw(struct bc_state *bcs)
+static void gigaset_freebcshw(struct bc_state *bcs)
 {
 	/* unused */
-	return 1;
 }
 
 /* Initialize the b-channel structure */
@@ -560,7 +559,7 @@ static int gigaset_initbcshw(struct bc_state *bcs)
 {
 	/* unused */
 	bcs->hw.usb = NULL;
-	return 1;
+	return 0;
 }
 
 static void gigaset_reinitbcshw(struct bc_state *bcs)
@@ -582,7 +581,7 @@ static int gigaset_initcshw(struct cardstate *cs)
 		kmalloc(sizeof(struct usb_cardstate), GFP_KERNEL);
 	if (!ucs) {
 		pr_err("out of memory\n");
-		return 0;
+		return -ENOMEM;
 	}
 
 	ucs->bchars[0] = 0;
@@ -597,7 +596,7 @@ static int gigaset_initcshw(struct cardstate *cs)
 	tasklet_init(&cs->write_tasklet,
 		     gigaset_modem_fill, (unsigned long) cs);
 
-	return 1;
+	return 0;
 }
 
 /* Send data from current skb to the device. */
@@ -766,9 +765,9 @@ static int gigaset_probe(struct usb_interface *interface,
 	if (startmode == SM_LOCKED)
 		cs->mstate = MS_LOCKED;
 
-	if (!gigaset_start(cs)) {
+	retval = gigaset_start(cs);
+	if (retval < 0) {
 		tasklet_kill(&cs->write_tasklet);
-		retval = -ENODEV;
 		goto error;
 	}
 	return 0;
@@ -898,8 +897,10 @@ static int __init usb_gigaset_init(void)
 	driver = gigaset_initdriver(GIGASET_MINOR, GIGASET_MINORS,
 				    GIGASET_MODULENAME, GIGASET_DEVNAME,
 				    &ops, THIS_MODULE);
-	if (driver == NULL)
+	if (driver == NULL) {
+		result = -ENOMEM;
 		goto error;
+	}
 
 	/* register this driver with the USB subsystem */
 	result = usb_register(&gigaset_usb_driver);
@@ -915,7 +916,7 @@ error:
 	if (driver)
 		gigaset_freedriver(driver);
 	driver = NULL;
-	return -1;
+	return result;
 }
 
 /*