[PATCH] usx2y cleanups and fixes

Sigh...
	a) mixing of userland and kernel pointers is bad
	b) so's not checking result of kmalloc()
	c) so's not checking result of copy_from_user()
	d) use of do { .... break; ... break; ... } while(0); is *highly*
unidiomatic.  Do not confuse kernel with IOCCC, please. And if you have
religious aversion to multiple return statements in a function, at least
learn the reasons why it is frowned upon in many situations.  Hint: they
all apply to use of break in that manner.
	e) 0 instead of NULL
Signed-off-by: Al Viro <viro@parcelfarce.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

sound/usb/usx2y/usX2Yhwdep.c

@@ -211,43 +211,50 @@ static int usX2Y_create_alsa_devices(snd_card_t* card)
 
 static int snd_usX2Y_hwdep_dsp_load(snd_hwdep_t *hw, snd_hwdep_dsp_image_t *dsp)
 {
-	int	lret, err;
-	char*	buf;
+	usX2Ydev_t *priv = hw->private_data;
+	int	lret, err = -EINVAL;
 	snd_printdd( "dsp_load %s\n", dsp->name);
 
-	buf = dsp->image;
-
-	err = -EINVAL;
 	if (access_ok(VERIFY_READ, dsp->image, dsp->length)) {
-		struct usb_device* dev = ((usX2Ydev_t*)hw->private_data)->chip.dev;
-		buf = kmalloc(dsp->length, GFP_KERNEL);
-		copy_from_user(buf, dsp->image, dsp->length);
-		if ((err = usb_set_interface(dev, 0, 1)))
+		struct usb_device* dev = priv->chip.dev;
+		char *buf = kmalloc(dsp->length, GFP_KERNEL);
+		if (!buf)
+			return -ENOMEM;
+		if (copy_from_user(buf, dsp->image, dsp->length)) {
+			kfree(buf);
+			return -EFAULT;
+		}
+		err = usb_set_interface(dev, 0, 1);
+		if (err)
 			snd_printk("usb_set_interface error \n");
 		else
 			err = usb_bulk_msg(dev, usb_sndbulkpipe(dev, 2), buf, dsp->length, &lret, 6*HZ);
 		kfree(buf);
 	}
-	if (!err  &&  1 == dsp->index)
-		do {
+	if (err)
+		return err;
+	if (dsp->index == 1) {
 		set_current_state(TASK_UNINTERRUPTIBLE);
 		schedule_timeout(HZ/4);			// give the device some time 
-			if ((err = usX2Y_AsyncSeq04_init((usX2Ydev_t*)hw->private_data))) {
+		err = usX2Y_AsyncSeq04_init(priv);
+		if (err) {
 			snd_printk("usX2Y_AsyncSeq04_init error \n");
-				break;
+			return err;
 		}
-			if ((err = usX2Y_In04_init((usX2Ydev_t*)hw->private_data))) {
+		err = usX2Y_In04_init(priv);
+		if (err) {
 			snd_printk("usX2Y_In04_init error \n");
-				break;
+			return err;
 		}
-			if ((err = usX2Y_create_alsa_devices(hw->card))) {
+		err = usX2Y_create_alsa_devices(hw->card);
+		if (err) {
 			snd_printk("usX2Y_create_alsa_devices error %i \n", err);
 			snd_card_free(hw->card);
-				break;
+			return err;
 		}
-			((usX2Ydev_t*)hw->private_data)->chip_status |= USX2Y_STAT_CHIP_INIT; 
+		priv->chip_status |= USX2Y_STAT_CHIP_INIT; 
 		snd_printdd("%s: alsa all started\n", hw->name);
-		} while (0);
+	}
 	return err;
 }
 

sound/usb/usx2y/usbusx2y.c

@@ -346,11 +346,11 @@ static void* usX2Y_usb_probe(struct usb_device* device, struct usb_interface *in
 	     device->descriptor.idProduct != USB_ID_US224 &&
 	     device->descriptor.idProduct != USB_ID_US428) ||
 	    !(card = usX2Y_create_card(device)))
-		return 0;
+		return NULL;
 	if ((err = usX2Y_hwdep_new(card, device)) < 0  ||
 	    (err = snd_card_register(card)) < 0) {
 		snd_card_free(card);
-		return 0;
+		return NULL;
 	}
 	return card;
 }

sound/usb/usx2y/usbusx2yaudio.c

@@ -411,7 +411,7 @@ static void usX2Y_urb_release(struct urb** urb, int free_tb)
 		if (free_tb)
 			kfree((*urb)->transfer_buffer);
 		usb_free_urb(*urb);
-		*urb = 0;
+		*urb = NULL;
 	}
 }
 /*
@@ -427,7 +427,7 @@ static void usX2Y_urbs_release(snd_usX2Y_substream_t *subs)
 
 	if (subs->tmpbuf) {
 		kfree(subs->tmpbuf);
-		subs->tmpbuf = 0;
+		subs->tmpbuf = NULL;
 	}
 }
 
@@ -794,7 +794,7 @@ static int snd_usX2Y_pcm_prepare(snd_pcm_substream_t *substream)
 				return err;
 		snd_printdd("starting capture pipe for playpipe\n");
 		usX2Y_urbs_allocate(capsubs);
-		capsubs->completed_urb = 0;
+		capsubs->completed_urb = NULL;
 		{
 			DECLARE_WAITQUEUE(wait, current);
 			add_wait_queue(&capsubs->wait_queue, &wait);
@@ -838,7 +838,7 @@ static int snd_usX2Y_pcm_prepare(snd_pcm_substream_t *substream)
 				}
 			}
 		}
-		subs->completed_urb = 0;
+		subs->completed_urb = NULL;
 		subs->next_urb_complete = -1;
 		subs->stalled = 0;
 	}