drivers/net/wireless/intersil/p54/p54usb.c

Source file repositories/reference/linux-study-clean/drivers/net/wireless/intersil/p54/p54usb.c

File Facts

System
Linux kernel
Corpus path
drivers/net/wireless/intersil/p54/p54usb.c
Extension
.c
Size
29750 bytes
Lines
1141
Domain
Driver Families
Bucket
drivers/net
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 (unlikely(!skb)) {
			/* TODO check rx queue length and refill *somewhere* */
			return;
		}

		info = (struct p54u_rx_info *) skb->cb;
		info->urb = urb;
		info->dev = dev;
		urb->transfer_buffer = skb_tail_pointer(skb);
		urb->context = skb;
	} else {
		if (priv->hw_type == P54U_NET2280)
			skb_push(skb, priv->common.tx_hdr_len);
		if (priv->common.fw_interface == FW_LM87) {
			skb_push(skb, 4);
			skb_put(skb, 4);
		}
		skb_reset_tail_pointer(skb);
		skb_trim(skb, 0);
		urb->transfer_buffer = skb_tail_pointer(skb);
	}
	skb_queue_tail(&priv->rx_queue, skb);
	usb_anchor_urb(urb, &priv->submitted);
	if (usb_submit_urb(urb, GFP_ATOMIC)) {
		skb_unlink(skb, &priv->rx_queue);
		usb_unanchor_urb(urb);
		dev_kfree_skb_irq(skb);
	}
}

static void p54u_tx_cb(struct urb *urb)
{
	struct sk_buff *skb = urb->context;
	struct ieee80211_hw *dev =
		usb_get_intfdata(usb_ifnum_to_if(urb->dev, 0));

	p54_free_skb(dev, skb);
}

static void p54u_tx_dummy_cb(struct urb *urb) { }

static void p54u_free_urbs(struct ieee80211_hw *dev)
{
	struct p54u_priv *priv = dev->priv;
	usb_kill_anchored_urbs(&priv->submitted);
}

static void p54u_stop(struct ieee80211_hw *dev)
{
	/*
	 * TODO: figure out how to reliably stop the 3887 and net2280 so
	 * the hardware is still usable next time we want to start it.
	 * until then, we just stop listening to the hardware..
	 */
	p54u_free_urbs(dev);
}

static int p54u_init_urbs(struct ieee80211_hw *dev)
{
	struct p54u_priv *priv = dev->priv;
	struct urb *entry = NULL;
	struct sk_buff *skb;
	struct p54u_rx_info *info;
	int ret = 0;

	while (skb_queue_len(&priv->rx_queue) < 32) {
		skb = __dev_alloc_skb(priv->common.rx_mtu + 32, GFP_KERNEL);
		if (!skb) {
			ret = -ENOMEM;
			goto err;
		}
		entry = usb_alloc_urb(0, GFP_KERNEL);
		if (!entry) {
			ret = -ENOMEM;
			goto err;
		}

		usb_fill_bulk_urb(entry, priv->udev,
				  usb_rcvbulkpipe(priv->udev, P54U_PIPE_DATA),
				  skb_tail_pointer(skb),
				  priv->common.rx_mtu + 32, p54u_rx_cb, skb);
		info = (struct p54u_rx_info *) skb->cb;
		info->urb = entry;
		info->dev = dev;
		skb_queue_tail(&priv->rx_queue, skb);

		usb_anchor_urb(entry, &priv->submitted);
		ret = usb_submit_urb(entry, GFP_KERNEL);
		if (ret) {
			skb_unlink(skb, &priv->rx_queue);

Annotation

Implementation Notes