int b43_dma_tx(struct b43_wldev *dev, struct sk_buff *skb)
{
struct b43_dmaring *ring;
struct ieee80211_hdr *hdr;
int err = 0;
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
hdr = (struct ieee80211_hdr *)skb->data;
if (info->flags & IEEE80211_TX_CTL_SEND_AFTER_DTIM) {
/* The multicast ring will be sent after the DTIM */
ring = dev->dma.tx_ring_mcast;
/* Set the more-data bit. Ucode will clear it on
* the last frame for us. */
hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREDATA);
} else {
/* Decide by priority where to put this frame. */
ring = select_ring_by_priority(
dev, skb_get_queue_mapping(skb));
}
B43_WARN_ON(!ring->tx);
if (unlikely(ring->stopped)) {
/* We get here only because of a bug in mac80211.
* Because of a race, one packet may be queued after
* the queue is stopped, thus we got called when we shouldn't.
* For now, just refuse the transmit. */
if (b43_debug(dev, B43_DBG_DMAVERBOSE))
b43err(dev->wl, "Packet after queue stopped\n");
err = -ENOSPC;
goto out;
}
if (unlikely(WARN_ON(free_slots(ring) < TX_SLOTS_PER_FRAME))) {
/* If we get here, we have a real error with the queue
* full, but queues not stopped. */
b43err(dev->wl, "DMA queue overflow\n");
err = -ENOSPC;
goto out;
}
/* Assign the queue number to the ring (if not already done before)
* so TX status handling can use it. The queue to ring mapping is
* static, so we don't need to store it per frame. */
ring->queue_prio = skb_get_queue_mapping(skb);
err = dma_tx_fragment(ring, skb);
if (unlikely(err == -ENOKEY)) {
/* Drop this packet, as we don't have the encryption key
* anymore and must not transmit it unencrypted. */
ieee80211_free_txskb(dev->wl->hw, skb);
err = 0;
goto out;
}
if (unlikely(err)) {
b43err(dev->wl, "DMA tx mapping failure\n");
goto out;
}
if ((free_slots(ring) < TX_SLOTS_PER_FRAME) ||
should_inject_overflow(ring)) {
/* This TX ring is full. */
unsigned int skb_mapping = skb_get_queue_mapping(skb);
ieee80211_stop_queue(dev->wl->hw, skb_mapping);
dev->wl->tx_queue_stopped[skb_mapping] = 1;
ring->stopped = true;
if (b43_debug(dev, B43_DBG_DMAVERBOSE)) {
b43dbg(dev->wl, "Stopped TX ring %d\n", ring->index);
}
}
out:
return err;
}
int b43_dma_tx(struct b43_wldev *dev, struct sk_buff *skb)
{
struct b43_dmaring *ring;
struct ieee80211_hdr *hdr;
int err = 0;
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
hdr = (struct ieee80211_hdr *)skb->data;
if (info->flags & IEEE80211_TX_CTL_SEND_AFTER_DTIM) {
ring = dev->dma.tx_ring_mcast;
hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREDATA);
} else {
ring = select_ring_by_priority(
dev, skb_get_queue_mapping(skb));
}
B43_WARN_ON(!ring->tx);
if (unlikely(ring->stopped)) {
if (b43_debug(dev, B43_DBG_DMAVERBOSE))
b43err(dev->wl, "Packet after queue stopped\n");
err = -ENOSPC;
goto out;
}
if (unlikely(WARN_ON(free_slots(ring) < TX_SLOTS_PER_FRAME))) {
b43err(dev->wl, "DMA queue overflow\n");
err = -ENOSPC;
goto out;
}
ring->queue_prio = skb_get_queue_mapping(skb);
err = dma_tx_fragment(ring, skb);
if (unlikely(err == -ENOKEY)) {
/* Drop this packet, as we don't have the encryption key
* anymore and must not transmit it unencrypted. */
ieee80211_free_txskb(dev->wl->hw, skb);
err = 0;
goto out;
}
if (unlikely(err)) {
b43err(dev->wl, "DMA tx mapping failure\n");
goto out;
}
if ((free_slots(ring) < TX_SLOTS_PER_FRAME) ||
should_inject_overflow(ring)) {
unsigned int skb_mapping = skb_get_queue_mapping(skb);
ieee80211_stop_queue(dev->wl->hw, skb_mapping);
dev->wl->tx_queue_stopped[skb_mapping] = 1;
ring->stopped = true;
if (b43_debug(dev, B43_DBG_DMAVERBOSE)) {
b43dbg(dev->wl, "Stopped TX ring %d\n", ring->index);
}
}
out:
return err;
}