diff --git a/drivers/media/usb/pwc/pwc-if.c b/drivers/media/usb/pwc/pwc-if.c
index 9b76cf133d52..3df7ca2357da 100644
--- a/drivers/media/usb/pwc/pwc-if.c
+++ b/drivers/media/usb/pwc/pwc-if.c
@@ -147,16 +147,17 @@ static const struct video_device pwc_template = {
 /***************************************************************************/
 /* Private functions */
 
-static void *pwc_alloc_urb_buffer(struct device *dev,
+static void *pwc_alloc_urb_buffer(struct usb_device *dev,
 				  size_t size, dma_addr_t *dma_handle)
 {
+	struct device *dmadev = dev->bus->sysdev;
 	void *buffer = kmalloc(size, GFP_KERNEL);
 
 	if (!buffer)
 		return NULL;
 
-	*dma_handle = dma_map_single(dev, buffer, size, DMA_FROM_DEVICE);
-	if (dma_mapping_error(dev, *dma_handle)) {
+	*dma_handle = dma_map_single(dmadev, buffer, size, DMA_FROM_DEVICE);
+	if (dma_mapping_error(dmadev, *dma_handle)) {
 		kfree(buffer);
 		return NULL;
 	}
@@ -164,12 +165,14 @@ static void *pwc_alloc_urb_buffer(struct device *dev,
 	return buffer;
 }
 
-static void pwc_free_urb_buffer(struct device *dev,
+static void pwc_free_urb_buffer(struct usb_device *dev,
 				size_t size,
 				void *buffer,
 				dma_addr_t dma_handle)
 {
-	dma_unmap_single(dev, dma_handle, size, DMA_FROM_DEVICE);
+	struct device *dmadev = dev->bus->sysdev;
+
+	dma_unmap_single(dmadev, dma_handle, size, DMA_FROM_DEVICE);
 	kfree(buffer);
 }
 
@@ -274,6 +277,7 @@ static void pwc_frame_complete(struct pwc_device *pdev)
 static void pwc_isoc_handler(struct urb *urb)
 {
 	struct pwc_device *pdev = (struct pwc_device *)urb->context;
+	struct device *dmadev = urb->dev->bus->sysdev;
 	int i, fst, flen;
 	unsigned char *iso_buf = NULL;
 
@@ -320,7 +324,7 @@ static void pwc_isoc_handler(struct urb *urb)
 	/* Reset ISOC error counter. We did get here, after all. */
 	pdev->visoc_errors = 0;
 
-	dma_sync_single_for_cpu(&urb->dev->dev,
+	dma_sync_single_for_cpu(dmadev,
 				urb->transfer_dma,
 				urb->transfer_buffer_length,
 				DMA_FROM_DEVICE);
@@ -371,7 +375,7 @@ static void pwc_isoc_handler(struct urb *urb)
 		pdev->vlast_packet_size = flen;
 	}
 
-	dma_sync_single_for_device(&urb->dev->dev,
+	dma_sync_single_for_device(dmadev,
 				   urb->transfer_dma,
 				   urb->transfer_buffer_length,
 				   DMA_FROM_DEVICE);
@@ -453,7 +457,7 @@ retry:
 		urb->pipe = usb_rcvisocpipe(udev, pdev->vendpoint);
 		urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
 		urb->transfer_buffer_length = ISO_BUFFER_SIZE;
-		urb->transfer_buffer = pwc_alloc_urb_buffer(&udev->dev,
+		urb->transfer_buffer = pwc_alloc_urb_buffer(udev,
 							    urb->transfer_buffer_length,
 							    &urb->transfer_dma);
 		if (urb->transfer_buffer == NULL) {
@@ -516,7 +520,7 @@ static void pwc_iso_free(struct pwc_device *pdev)
 		if (urb) {
 			PWC_DEBUG_MEMORY("Freeing URB\n");
 			if (urb->transfer_buffer)
-				pwc_free_urb_buffer(&urb->dev->dev,
+				pwc_free_urb_buffer(urb->dev,
 						    urb->transfer_buffer_length,
 						    urb->transfer_buffer,
 						    urb->transfer_dma);