* On LAST_PACKET, a new frame is returned.
  */
 struct gspca_frame *gspca_frame_add(struct gspca_dev *gspca_dev,
-                                   int packet_type,
+                                   enum gspca_packet_type packet_type,
                                    struct gspca_frame *frame,
                                    const __u8 *data,
                                    int len)
        void *mem;
        unsigned long adr;
 
-/*     size = PAGE_ALIGN(size);        (already done) */
        mem = vmalloc_32(size);
        if (mem != NULL) {
                adr = (unsigned long) mem;
 
        memset(cap, 0, sizeof *cap);
        strncpy(cap->driver, gspca_dev->sd_desc->name, sizeof cap->driver);
-/*     strncpy(cap->card, gspca_dev->cam.dev_name, sizeof cap->card); */
        if (gspca_dev->dev->product != NULL) {
                strncpy(cap->card, gspca_dev->dev->product,
                        sizeof cap->card);
        }
 
        frame->v4l2_buf.flags |= V4L2_BUF_FLAG_QUEUED;
-/*     frame->v4l2_buf.flags &= ~V4L2_BUF_FLAG_DONE; */
 
        if (frame->v4l2_buf.memory == V4L2_MEMORY_USERPTR) {
                frame->v4l2_buf.m.userptr = v4l2_buf->m.userptr;
        if (dev_size < sizeof *gspca_dev)
                dev_size = sizeof *gspca_dev;
        gspca_dev = kzalloc(dev_size, GFP_KERNEL);
-       if (gspca_dev == NULL) {
+       if (!gspca_dev) {
                err("couldn't kzalloc gspca struct");
-               return -EIO;
+               return -ENOMEM;
        }
        kref_init(&gspca_dev->kref);
        gspca_dev->usb_buf = kmalloc(USB_BUF_SZ, GFP_KERNEL);
        if (!gspca_dev->usb_buf) {
                err("out of memory");
-               ret = -EIO;
+               ret = -ENOMEM;
                goto out;
        }
        gspca_dev->dev = dev;
        gspca_dev->iface = interface->bInterfaceNumber;
        gspca_dev->nbalt = intf->num_altsetting;
        gspca_dev->sd_desc = sd_desc;
-/*     gspca_dev->users = 0;                   (done by kzalloc) */
        gspca_dev->nbufread = 2;
 
        /* configure the subdriver and initialize the USB device */
 
 };
 
 /* packet types when moving from iso buf to frame buf */
-#define DISCARD_PACKET 0
-#define FIRST_PACKET   1
-#define INTER_PACKET   2
-#define LAST_PACKET    3
+enum gspca_packet_type {
+       DISCARD_PACKET,
+       FIRST_PACKET,
+       INTER_PACKET,
+       LAST_PACKET
+};
 
 struct gspca_frame {
        __u8 *data;                     /* frame buffer */
                struct module *module);
 void gspca_disconnect(struct usb_interface *intf);
 struct gspca_frame *gspca_frame_add(struct gspca_dev *gspca_dev,
-                                   int packet_type,
+                                   enum gspca_packet_type packet_type,
                                    struct gspca_frame *frame,
                                    const __u8 *data,
                                    int len);