Linux debugging

Check our new training course

Linux debugging, tracing, profiling & perf. analysis

Check our new training course
with Creative Commons CC-BY-SA
lecture and lab materials

Bootlin logo

Elixir Cross Referencer

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
/*
 * NXP Wireless LAN device driver: AP TX and RX data handling
 *
 * Copyright 2011-2020 NXP
 *
 * This software file (the "File") is distributed by NXP
 * under the terms of the GNU General Public License Version 2, June 1991
 * (the "License").  You may use, redistribute and/or modify this File in
 * accordance with the terms and conditions of the License, a copy of which
 * is available by writing to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA or on the
 * worldwide web at http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt.
 *
 * THE FILE IS DISTRIBUTED AS-IS, WITHOUT WARRANTY OF ANY KIND, AND THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE
 * ARE EXPRESSLY DISCLAIMED.  The License provides additional details about
 * this warranty disclaimer.
 */

#include "decl.h"
#include "ioctl.h"
#include "main.h"
#include "wmm.h"
#include "11n_aggr.h"
#include "11n_rxreorder.h"

/* This function checks if particular RA list has packets more than low bridge
 * packet threshold and then deletes packet from this RA list.
 * Function deletes packets from such RA list and returns true. If no such list
 * is found, false is returned.
 */
static bool
mwifiex_uap_del_tx_pkts_in_ralist(struct mwifiex_private *priv,
				  struct list_head *ra_list_head,
				  int tid)
{
	struct mwifiex_ra_list_tbl *ra_list;
	struct sk_buff *skb, *tmp;
	bool pkt_deleted = false;
	struct mwifiex_txinfo *tx_info;
	struct mwifiex_adapter *adapter = priv->adapter;

	list_for_each_entry(ra_list, ra_list_head, list) {
		if (skb_queue_empty(&ra_list->skb_head))
			continue;

		skb_queue_walk_safe(&ra_list->skb_head, skb, tmp) {
			tx_info = MWIFIEX_SKB_TXCB(skb);
			if (tx_info->flags & MWIFIEX_BUF_FLAG_BRIDGED_PKT) {
				__skb_unlink(skb, &ra_list->skb_head);
				mwifiex_write_data_complete(adapter, skb, 0,
							    -1);
				if (ra_list->tx_paused)
					priv->wmm.pkts_paused[tid]--;
				else
					atomic_dec(&priv->wmm.tx_pkts_queued);
				pkt_deleted = true;
			}
			if ((atomic_read(&adapter->pending_bridged_pkts) <=
					     MWIFIEX_BRIDGED_PKTS_THR_LOW))
				break;
		}
	}

	return pkt_deleted;
}

/* This function deletes packets from particular RA List. RA list index
 * from which packets are deleted is preserved so that packets from next RA
 * list are deleted upon subsequent call thus maintaining fairness.
 */
static void mwifiex_uap_cleanup_tx_queues(struct mwifiex_private *priv)
{
	struct list_head *ra_list;
	int i;

	spin_lock_bh(&priv->wmm.ra_list_spinlock);

	for (i = 0; i < MAX_NUM_TID; i++, priv->del_list_idx++) {
		if (priv->del_list_idx == MAX_NUM_TID)
			priv->del_list_idx = 0;
		ra_list = &priv->wmm.tid_tbl_ptr[priv->del_list_idx].ra_list;
		if (mwifiex_uap_del_tx_pkts_in_ralist(priv, ra_list, i)) {
			priv->del_list_idx++;
			break;
		}
	}

	spin_unlock_bh(&priv->wmm.ra_list_spinlock);
}


static void mwifiex_uap_queue_bridged_pkt(struct mwifiex_private *priv,
					 struct sk_buff *skb)
{
	struct mwifiex_adapter *adapter = priv->adapter;
	struct uap_rxpd *uap_rx_pd;
	struct rx_packet_hdr *rx_pkt_hdr;
	struct sk_buff *new_skb;
	struct mwifiex_txinfo *tx_info;
	int hdr_chop;
	struct ethhdr *p_ethhdr;
	struct mwifiex_sta_node *src_node;
	int index;

	uap_rx_pd = (struct uap_rxpd *)(skb->data);
	rx_pkt_hdr = (void *)uap_rx_pd + le16_to_cpu(uap_rx_pd->rx_pkt_offset);

	if ((atomic_read(&adapter->pending_bridged_pkts) >=
					     MWIFIEX_BRIDGED_PKTS_THR_HIGH)) {
		mwifiex_dbg(priv->adapter, ERROR,
			    "Tx: Bridge packet limit reached. Drop packet!\n");
		kfree_skb(skb);
		mwifiex_uap_cleanup_tx_queues(priv);
		return;
	}

	if ((!memcmp(&rx_pkt_hdr->rfc1042_hdr, bridge_tunnel_header,
		     sizeof(bridge_tunnel_header))) ||
	    (!memcmp(&rx_pkt_hdr->rfc1042_hdr, rfc1042_header,
		     sizeof(rfc1042_header)) &&
	     ntohs(rx_pkt_hdr->rfc1042_hdr.snap_type) != ETH_P_AARP &&
	     ntohs(rx_pkt_hdr->rfc1042_hdr.snap_type) != ETH_P_IPX)) {
		/* Replace the 803 header and rfc1042 header (llc/snap) with
		 * an Ethernet II header, keep the src/dst and snap_type
		 * (ethertype).
		 *
		 * The firmware only passes up SNAP frames converting all RX
		 * data from 802.11 to 802.2/LLC/SNAP frames.
		 *
		 * To create the Ethernet II, just move the src, dst address
		 * right before the snap_type.
		 */
		p_ethhdr = (struct ethhdr *)
			((u8 *)(&rx_pkt_hdr->eth803_hdr)
			 + sizeof(rx_pkt_hdr->eth803_hdr)
			 + sizeof(rx_pkt_hdr->rfc1042_hdr)
			 - sizeof(rx_pkt_hdr->eth803_hdr.h_dest)
			 - sizeof(rx_pkt_hdr->eth803_hdr.h_source)
			 - sizeof(rx_pkt_hdr->rfc1042_hdr.snap_type));
		memcpy(p_ethhdr->h_source, rx_pkt_hdr->eth803_hdr.h_source,
		       sizeof(p_ethhdr->h_source));
		memcpy(p_ethhdr->h_dest, rx_pkt_hdr->eth803_hdr.h_dest,
		       sizeof(p_ethhdr->h_dest));
		/* Chop off the rxpd + the excess memory from
		 * 802.2/llc/snap header that was removed.
		 */
		hdr_chop = (u8 *)p_ethhdr - (u8 *)uap_rx_pd;
	} else {
		/* Chop off the rxpd */
		hdr_chop = (u8 *)&rx_pkt_hdr->eth803_hdr - (u8 *)uap_rx_pd;
	}

	/* Chop off the leading header bytes so that it points
	 * to the start of either the reconstructed EthII frame
	 * or the 802.2/llc/snap frame.
	 */
	skb_pull(skb, hdr_chop);

	if (skb_headroom(skb) < MWIFIEX_MIN_DATA_HEADER_LEN) {
		mwifiex_dbg(priv->adapter, ERROR,
			    "data: Tx: insufficient skb headroom %d\n",
			    skb_headroom(skb));
		/* Insufficient skb headroom - allocate a new skb */
		new_skb =
			skb_realloc_headroom(skb, MWIFIEX_MIN_DATA_HEADER_LEN);
		if (unlikely(!new_skb)) {
			mwifiex_dbg(priv->adapter, ERROR,
				    "Tx: cannot allocate new_skb\n");
			kfree_skb(skb);
			priv->stats.tx_dropped++;
			return;
		}

		kfree_skb(skb);
		skb = new_skb;
		mwifiex_dbg(priv->adapter, INFO,
			    "info: new skb headroom %d\n",
			    skb_headroom(skb));
	}

	tx_info = MWIFIEX_SKB_TXCB(skb);
	memset(tx_info, 0, sizeof(*tx_info));
	tx_info->bss_num = priv->bss_num;
	tx_info->bss_type = priv->bss_type;
	tx_info->flags |= MWIFIEX_BUF_FLAG_BRIDGED_PKT;

	src_node = mwifiex_get_sta_entry(priv, rx_pkt_hdr->eth803_hdr.h_source);
	if (src_node) {
		src_node->stats.last_rx = jiffies;
		src_node->stats.rx_bytes += skb->len;
		src_node->stats.rx_packets++;
		src_node->stats.last_tx_rate = uap_rx_pd->rx_rate;
		src_node->stats.last_tx_htinfo = uap_rx_pd->ht_info;
	}

	if (is_unicast_ether_addr(rx_pkt_hdr->eth803_hdr.h_dest)) {
		/* Update bridge packet statistics as the
		 * packet is not going to kernel/upper layer.
		 */
		priv->stats.rx_bytes += skb->len;
		priv->stats.rx_packets++;

		/* Sending bridge packet to TX queue, so save the packet
		 * length in TXCB to update statistics in TX complete.
		 */
		tx_info->pkt_len = skb->len;
	}

	__net_timestamp(skb);

	index = mwifiex_1d_to_wmm_queue[skb->priority];
	atomic_inc(&priv->wmm_tx_pending[index]);
	mwifiex_wmm_add_buf_txqueue(priv, skb);
	atomic_inc(&adapter->tx_pending);
	atomic_inc(&adapter->pending_bridged_pkts);

	mwifiex_queue_main_work(priv->adapter);

	return;
}

/*
 * This function contains logic for AP packet forwarding.
 *
 * If a packet is multicast/broadcast, it is sent to kernel/upper layer
 * as well as queued back to AP TX queue so that it can be sent to other
 * associated stations.
 * If a packet is unicast and RA is present in associated station list,
 * it is again requeued into AP TX queue.
 * If a packet is unicast and RA is not in associated station list,
 * packet is forwarded to kernel to handle routing logic.
 */
int mwifiex_handle_uap_rx_forward(struct mwifiex_private *priv,
				  struct sk_buff *skb)
{
	struct mwifiex_adapter *adapter = priv->adapter;
	struct uap_rxpd *uap_rx_pd;
	struct rx_packet_hdr *rx_pkt_hdr;
	u8 ra[ETH_ALEN];
	struct sk_buff *skb_uap;

	uap_rx_pd = (struct uap_rxpd *)(skb->data);
	rx_pkt_hdr = (void *)uap_rx_pd + le16_to_cpu(uap_rx_pd->rx_pkt_offset);

	/* don't do packet forwarding in disconnected state */
	if (!priv->media_connected) {
		mwifiex_dbg(adapter, ERROR,
			    "drop packet in disconnected state.\n");
		dev_kfree_skb_any(skb);
		return 0;
	}

	memcpy(ra, rx_pkt_hdr->eth803_hdr.h_dest, ETH_ALEN);

	if (is_multicast_ether_addr(ra)) {
		skb_uap = skb_copy(skb, GFP_ATOMIC);
		mwifiex_uap_queue_bridged_pkt(priv, skb_uap);
	} else {
		if (mwifiex_get_sta_entry(priv, ra)) {
			/* Requeue Intra-BSS packet */
			mwifiex_uap_queue_bridged_pkt(priv, skb);
			return 0;
		}
	}

	/* Forward unicat/Inter-BSS packets to kernel. */
	return mwifiex_process_rx_packet(priv, skb);
}

int mwifiex_uap_recv_packet(struct mwifiex_private *priv,
			    struct sk_buff *skb)
{
	struct mwifiex_adapter *adapter = priv->adapter;
	struct mwifiex_sta_node *src_node;
	struct ethhdr *p_ethhdr;
	struct sk_buff *skb_uap;
	struct mwifiex_txinfo *tx_info;

	if (!skb)
		return -1;

	p_ethhdr = (void *)skb->data;
	src_node = mwifiex_get_sta_entry(priv, p_ethhdr->h_source);
	if (src_node) {
		src_node->stats.last_rx = jiffies;
		src_node->stats.rx_bytes += skb->len;
		src_node->stats.rx_packets++;
	}

	if (is_multicast_ether_addr(p_ethhdr->h_dest) ||
	    mwifiex_get_sta_entry(priv, p_ethhdr->h_dest)) {
		if (skb_headroom(skb) < MWIFIEX_MIN_DATA_HEADER_LEN)
			skb_uap =
			skb_realloc_headroom(skb, MWIFIEX_MIN_DATA_HEADER_LEN);
		else
			skb_uap = skb_copy(skb, GFP_ATOMIC);

		if (likely(skb_uap)) {
			tx_info = MWIFIEX_SKB_TXCB(skb_uap);
			memset(tx_info, 0, sizeof(*tx_info));
			tx_info->bss_num = priv->bss_num;
			tx_info->bss_type = priv->bss_type;
			tx_info->flags |= MWIFIEX_BUF_FLAG_BRIDGED_PKT;
			__net_timestamp(skb_uap);
			mwifiex_wmm_add_buf_txqueue(priv, skb_uap);
			atomic_inc(&adapter->tx_pending);
			atomic_inc(&adapter->pending_bridged_pkts);
			if ((atomic_read(&adapter->pending_bridged_pkts) >=
					MWIFIEX_BRIDGED_PKTS_THR_HIGH)) {
				mwifiex_dbg(adapter, ERROR,
					    "Tx: Bridge packet limit reached. Drop packet!\n");
				mwifiex_uap_cleanup_tx_queues(priv);
			}

		} else {
			mwifiex_dbg(adapter, ERROR, "failed to allocate skb_uap");
		}

		mwifiex_queue_main_work(adapter);
		/* Don't forward Intra-BSS unicast packet to upper layer*/
		if (mwifiex_get_sta_entry(priv, p_ethhdr->h_dest))
			return 0;
	}

	skb->dev = priv->netdev;
	skb->protocol = eth_type_trans(skb, priv->netdev);
	skb->ip_summed = CHECKSUM_NONE;

	/* This is required only in case of 11n and USB/PCIE as we alloc
	 * a buffer of 4K only if its 11N (to be able to receive 4K
	 * AMSDU packets). In case of SD we allocate buffers based
	 * on the size of packet and hence this is not needed.
	 *
	 * Modifying the truesize here as our allocation for each
	 * skb is 4K but we only receive 2K packets and this cause
	 * the kernel to start dropping packets in case where
	 * application has allocated buffer based on 2K size i.e.
	 * if there a 64K packet received (in IP fragments and
	 * application allocates 64K to receive this packet but
	 * this packet would almost double up because we allocate
	 * each 1.5K fragment in 4K and pass it up. As soon as the
	 * 64K limit hits kernel will start to drop rest of the
	 * fragments. Currently we fail the Filesndl-ht.scr script
	 * for UDP, hence this fix
	 */
	if ((adapter->iface_type == MWIFIEX_USB ||
	     adapter->iface_type == MWIFIEX_PCIE) &&
	    skb->truesize > MWIFIEX_RX_DATA_BUF_SIZE)
		skb->truesize += (skb->len - MWIFIEX_RX_DATA_BUF_SIZE);

	/* Forward multicast/broadcast packet to upper layer*/
	if (in_interrupt())
		netif_rx(skb);
	else
		netif_rx_ni(skb);

	return 0;
}

/*
 * This function processes the packet received on AP interface.
 *
 * The function looks into the RxPD and performs sanity tests on the
 * received buffer to ensure its a valid packet before processing it
 * further. If the packet is determined to be aggregated, it is
 * de-aggregated accordingly. Then skb is passed to AP packet forwarding logic.
 *
 * The completion callback is called after processing is complete.
 */
int mwifiex_process_uap_rx_packet(struct mwifiex_private *priv,
				  struct sk_buff *skb)
{
	struct mwifiex_adapter *adapter = priv->adapter;
	int ret;
	struct uap_rxpd *uap_rx_pd;
	struct rx_packet_hdr *rx_pkt_hdr;
	u16 rx_pkt_type;
	u8 ta[ETH_ALEN], pkt_type;
	struct mwifiex_sta_node *node;

	uap_rx_pd = (struct uap_rxpd *)(skb->data);
	rx_pkt_type = le16_to_cpu(uap_rx_pd->rx_pkt_type);
	rx_pkt_hdr = (void *)uap_rx_pd + le16_to_cpu(uap_rx_pd->rx_pkt_offset);

	ether_addr_copy(ta, rx_pkt_hdr->eth803_hdr.h_source);

	if ((le16_to_cpu(uap_rx_pd->rx_pkt_offset) +
	     le16_to_cpu(uap_rx_pd->rx_pkt_length)) > (u16) skb->len) {
		mwifiex_dbg(adapter, ERROR,
			    "wrong rx packet: len=%d, offset=%d, length=%d\n",
			    skb->len, le16_to_cpu(uap_rx_pd->rx_pkt_offset),
			    le16_to_cpu(uap_rx_pd->rx_pkt_length));
		priv->stats.rx_dropped++;

		node = mwifiex_get_sta_entry(priv, ta);
		if (node)
			node->stats.tx_failed++;

		dev_kfree_skb_any(skb);
		return 0;
	}

	if (rx_pkt_type == PKT_TYPE_MGMT) {
		ret = mwifiex_process_mgmt_packet(priv, skb);
		if (ret)
			mwifiex_dbg(adapter, DATA, "Rx of mgmt packet failed");
		dev_kfree_skb_any(skb);
		return ret;
	}


	if (rx_pkt_type != PKT_TYPE_BAR && uap_rx_pd->priority < MAX_NUM_TID) {
		spin_lock_bh(&priv->sta_list_spinlock);
		node = mwifiex_get_sta_entry(priv, ta);
		if (node)
			node->rx_seq[uap_rx_pd->priority] =
						le16_to_cpu(uap_rx_pd->seq_num);
		spin_unlock_bh(&priv->sta_list_spinlock);
	}

	if (!priv->ap_11n_enabled ||
	    (!mwifiex_11n_get_rx_reorder_tbl(priv, uap_rx_pd->priority, ta) &&
	    (le16_to_cpu(uap_rx_pd->rx_pkt_type) != PKT_TYPE_AMSDU))) {
		ret = mwifiex_handle_uap_rx_forward(priv, skb);
		return ret;
	}

	/* Reorder and send to kernel */
	pkt_type = (u8)le16_to_cpu(uap_rx_pd->rx_pkt_type);
	ret = mwifiex_11n_rx_reorder_pkt(priv, le16_to_cpu(uap_rx_pd->seq_num),
					 uap_rx_pd->priority, ta, pkt_type,
					 skb);

	if (ret || (rx_pkt_type == PKT_TYPE_BAR))
		dev_kfree_skb_any(skb);

	if (ret)
		priv->stats.rx_dropped++;

	return ret;
}

/*
 * This function fills the TxPD for AP tx packets.
 *
 * The Tx buffer received by this function should already have the
 * header space allocated for TxPD.
 *
 * This function inserts the TxPD in between interface header and actual
 * data and adjusts the buffer pointers accordingly.
 *
 * The following TxPD fields are set by this function, as required -
 *      - BSS number
 *      - Tx packet length and offset
 *      - Priority
 *      - Packet delay
 *      - Priority specific Tx control
 *      - Flags
 */
void *mwifiex_process_uap_txpd(struct mwifiex_private *priv,
			       struct sk_buff *skb)
{
	struct mwifiex_adapter *adapter = priv->adapter;
	struct uap_txpd *txpd;
	struct mwifiex_txinfo *tx_info = MWIFIEX_SKB_TXCB(skb);
	int pad;
	u16 pkt_type, pkt_offset;
	int hroom = adapter->intf_hdr_len;

	if (!skb->len) {
		mwifiex_dbg(adapter, ERROR,
			    "Tx: bad packet length: %d\n", skb->len);
		tx_info->status_code = -1;
		return skb->data;
	}

	BUG_ON(skb_headroom(skb) < MWIFIEX_MIN_DATA_HEADER_LEN);

	pkt_type = mwifiex_is_skb_mgmt_frame(skb) ? PKT_TYPE_MGMT : 0;

	pad = ((void *)skb->data - (sizeof(*txpd) + hroom) - NULL) &
			(MWIFIEX_DMA_ALIGN_SZ - 1);

	skb_push(skb, sizeof(*txpd) + pad);

	txpd = (struct uap_txpd *)skb->data;
	memset(txpd, 0, sizeof(*txpd));
	txpd->bss_num = priv->bss_num;
	txpd->bss_type = priv->bss_type;
	txpd->tx_pkt_length = cpu_to_le16((u16)(skb->len - (sizeof(*txpd) +
						pad)));
	txpd->priority = (u8)skb->priority;

	txpd->pkt_delay_2ms = mwifiex_wmm_compute_drv_pkt_delay(priv, skb);

	if (tx_info->flags & MWIFIEX_BUF_FLAG_EAPOL_TX_STATUS ||
	    tx_info->flags & MWIFIEX_BUF_FLAG_ACTION_TX_STATUS) {
		txpd->tx_token_id = tx_info->ack_frame_id;
		txpd->flags |= MWIFIEX_TXPD_FLAGS_REQ_TX_STATUS;
	}

	if (txpd->priority < ARRAY_SIZE(priv->wmm.user_pri_pkt_tx_ctrl))
		/*
		 * Set the priority specific tx_control field, setting of 0 will
		 * cause the default value to be used later in this function.
		 */
		txpd->tx_control =
		    cpu_to_le32(priv->wmm.user_pri_pkt_tx_ctrl[txpd->priority]);

	/* Offset of actual data */
	pkt_offset = sizeof(*txpd) + pad;
	if (pkt_type == PKT_TYPE_MGMT) {
		/* Set the packet type and add header for management frame */
		txpd->tx_pkt_type = cpu_to_le16(pkt_type);
		pkt_offset += MWIFIEX_MGMT_FRAME_HEADER_SIZE;
	}

	txpd->tx_pkt_offset = cpu_to_le16(pkt_offset);

	/* make space for adapter->intf_hdr_len */
	skb_push(skb, hroom);

	if (!txpd->tx_control)
		/* TxCtrl set by user or default */
		txpd->tx_control = cpu_to_le32(priv->pkt_tx_ctrl);

	return skb->data;
}