drivers/media/usb/au0828/au0828-video.c

Source file repositories/reference/linux-study-clean/drivers/media/usb/au0828/au0828-video.c

File Facts

System
Linux kernel
Corpus path
drivers/media/usb/au0828/au0828-video.c
Extension
.c
Size
53993 bytes
Lines
2061
Domain
Driver Families
Bucket
drivers/media
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

if (urb) {
			if (!irqs_disabled())
				usb_kill_urb(urb);
			else
				usb_unlink_urb(urb);

			if (dev->isoc_ctl.transfer_buffer[i]) {
				usb_free_coherent(dev->usbdev,
					urb->transfer_buffer_length,
					dev->isoc_ctl.transfer_buffer[i],
					urb->transfer_dma);
			}
			usb_free_urb(urb);
			dev->isoc_ctl.urb[i] = NULL;
		}
		dev->isoc_ctl.transfer_buffer[i] = NULL;
	}

	kfree(dev->isoc_ctl.urb);
	kfree(dev->isoc_ctl.transfer_buffer);

	dev->isoc_ctl.urb = NULL;
	dev->isoc_ctl.transfer_buffer = NULL;
	dev->isoc_ctl.num_bufs = 0;

	dev->stream_state = STREAM_OFF;
}

/*
 * Allocate URBs and start IRQ
 */
static int au0828_init_isoc(struct au0828_dev *dev, int max_packets,
			    int num_bufs, int max_pkt_size,
			    int (*isoc_copy) (struct au0828_dev *dev, struct urb *urb))
{
	struct au0828_dmaqueue *dma_q = &dev->vidq;
	int i;
	int sb_size, pipe;
	struct urb *urb;
	int j, k;
	int rc;

	au0828_isocdbg("au0828: called au0828_prepare_isoc\n");

	dev->isoc_ctl.isoc_copy = isoc_copy;
	dev->isoc_ctl.num_bufs = num_bufs;

	dev->isoc_ctl.urb = kcalloc(num_bufs, sizeof(void *),  GFP_KERNEL);
	if (!dev->isoc_ctl.urb) {
		au0828_isocdbg("cannot alloc memory for usb buffers\n");
		return -ENOMEM;
	}

	dev->isoc_ctl.transfer_buffer = kcalloc(num_bufs, sizeof(void *),
						GFP_KERNEL);
	if (!dev->isoc_ctl.transfer_buffer) {
		au0828_isocdbg("cannot allocate memory for usb transfer\n");
		kfree(dev->isoc_ctl.urb);
		return -ENOMEM;
	}

	dev->isoc_ctl.max_pkt_size = max_pkt_size;
	dev->isoc_ctl.buf = NULL;

	sb_size = max_packets * dev->isoc_ctl.max_pkt_size;

	/* allocate urbs and transfer buffers */
	for (i = 0; i < dev->isoc_ctl.num_bufs; i++) {
		urb = usb_alloc_urb(max_packets, GFP_KERNEL);
		if (!urb) {
			au0828_isocdbg("cannot allocate URB\n");
			au0828_uninit_isoc(dev);
			return -ENOMEM;
		}
		dev->isoc_ctl.urb[i] = urb;

		dev->isoc_ctl.transfer_buffer[i] = usb_alloc_coherent(dev->usbdev,
			sb_size, GFP_KERNEL, &urb->transfer_dma);
		if (!dev->isoc_ctl.transfer_buffer[i]) {
			au0828_isocdbg("cannot allocate transfer buffer\n");
			au0828_uninit_isoc(dev);
			return -ENOMEM;
		}
		memset(dev->isoc_ctl.transfer_buffer[i], 0, sb_size);

		pipe = usb_rcvisocpipe(dev->usbdev,
				       dev->isoc_in_endpointaddr);

		usb_fill_int_urb(urb, dev->usbdev, pipe,
				 dev->isoc_ctl.transfer_buffer[i], sb_size,

Annotation

Implementation Notes