[deliverable/linux.git] / drivers / net / wireless / ath / ath9k / dfs_pattern_detector.c

/*
 * Copyright (c) 2012 Neratec Solutions AG
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <linux/slab.h>
#include <linux/export.h>

#include "dfs_pattern_detector.h"
#include "dfs_pri_detector.h"
#include "ath9k.h"

/*
 * tolerated deviation of radar time stamp in usecs on both sides
 * TODO: this might need to be HW-dependent
 */
#define PRI_TOLERANCE	16

/**
 * struct radar_types - contains array of patterns defined for one DFS domain
 * @domain: DFS regulatory domain
 * @num_radar_types: number of radar types to follow
 * @radar_types: radar types array
 */
struct radar_types {
	enum nl80211_dfs_regions region;
	u32 num_radar_types;
	const struct radar_detector_specs *radar_types;
};

/* percentage on ppb threshold to trigger detection */
#define MIN_PPB_THRESH	50
#define PPB_THRESH(PPB) ((PPB * MIN_PPB_THRESH + 50) / 100)
#define PRF2PRI(PRF) ((1000000 + PRF / 2) / PRF)
/* percentage of pulse width tolerance */
#define WIDTH_TOLERANCE 5
#define WIDTH_LOWER(X) ((X*(100-WIDTH_TOLERANCE)+50)/100)
#define WIDTH_UPPER(X) ((X*(100+WIDTH_TOLERANCE)+50)/100)

#define ETSI_PATTERN(ID, WMIN, WMAX, PMIN, PMAX, PRF, PPB)	\
{								\
	ID, WIDTH_LOWER(WMIN), WIDTH_UPPER(WMAX),		\
	(PRF2PRI(PMAX) - PRI_TOLERANCE),			\
	(PRF2PRI(PMIN) * PRF + PRI_TOLERANCE), PRF, PPB * PRF,	\
	PPB_THRESH(PPB), PRI_TOLERANCE,				\
}

/* radar types as defined by ETSI EN-301-893 v1.5.1 */
static const struct radar_detector_specs etsi_radar_ref_types_v15[] = {
	ETSI_PATTERN(0,  0,  1,  700,  700, 1, 18),
	ETSI_PATTERN(1,  0,  5,  200, 1000, 1, 10),
	ETSI_PATTERN(2,  0, 15,  200, 1600, 1, 15),
	ETSI_PATTERN(3,  0, 15, 2300, 4000, 1, 25),
	ETSI_PATTERN(4, 20, 30, 2000, 4000, 1, 20),
	ETSI_PATTERN(5,  0,  2,  300,  400, 3, 10),
	ETSI_PATTERN(6,  0,  2,  400, 1200, 3, 15),
};

static const struct radar_types etsi_radar_types_v15 = {
	.region			= NL80211_DFS_ETSI,
	.num_radar_types	= ARRAY_SIZE(etsi_radar_ref_types_v15),
	.radar_types		= etsi_radar_ref_types_v15,
};

/* for now, we support ETSI radar types, FCC and JP are TODO */
static const struct radar_types *dfs_domains[] = {
	&etsi_radar_types_v15,
};

/**
 * get_dfs_domain_radar_types() - get radar types for a given DFS domain
 * @param domain DFS domain
 * @return radar_types ptr on success, NULL if DFS domain is not supported
 */
static const struct radar_types *
get_dfs_domain_radar_types(enum nl80211_dfs_regions region)
{
	u32 i;
	for (i = 0; i < ARRAY_SIZE(dfs_domains); i++) {
		if (dfs_domains[i]->region == region)
			return dfs_domains[i];
	}
	return NULL;
}

/**
 * struct channel_detector - detector elements for a DFS channel
 * @head: list_head
 * @freq: frequency for this channel detector in MHz
 * @detectors: array of dynamically created detector elements for this freq
 *
 * Channel detectors are required to provide multi-channel DFS detection, e.g.
 * to support off-channel scanning. A pattern detector has a list of channels
 * radar pulses have been reported for in the past.
 */
struct channel_detector {
	struct list_head head;
	u16 freq;
	struct pri_detector **detectors;
};

/* channel_detector_reset() - reset detector lines for a given channel */
static void channel_detector_reset(struct dfs_pattern_detector *dpd,
				   struct channel_detector *cd)
{
	u32 i;
	if (cd == NULL)
		return;
	for (i = 0; i < dpd->num_radar_types; i++)
		cd->detectors[i]->reset(cd->detectors[i], dpd->last_pulse_ts);
}

/* channel_detector_exit() - destructor */
static void channel_detector_exit(struct dfs_pattern_detector *dpd,
				  struct channel_detector *cd)
{
	u32 i;
	if (cd == NULL)
		return;
	list_del(&cd->head);
	for (i = 0; i < dpd->num_radar_types; i++) {
		struct pri_detector *de = cd->detectors[i];
		if (de != NULL)
			de->exit(de);
	}
	kfree(cd->detectors);
	kfree(cd);
}

static struct channel_detector *
channel_detector_create(struct dfs_pattern_detector *dpd, u16 freq)
{
	u32 sz, i;
	struct channel_detector *cd;
	struct ath_common *common = ath9k_hw_common(dpd->ah);

	cd = kmalloc(sizeof(*cd), GFP_ATOMIC);
	if (cd == NULL)
		goto fail;

	INIT_LIST_HEAD(&cd->head);
	cd->freq = freq;
	sz = sizeof(cd->detectors) * dpd->num_radar_types;
	cd->detectors = kzalloc(sz, GFP_ATOMIC);
	if (cd->detectors == NULL)
		goto fail;

	for (i = 0; i < dpd->num_radar_types; i++) {
		const struct radar_detector_specs *rs = &dpd->radar_spec[i];
		struct pri_detector *de = pri_detector_init(rs);
		if (de == NULL)
			goto fail;
		cd->detectors[i] = de;
	}
	list_add(&cd->head, &dpd->channel_detectors);
	return cd;

fail:
	ath_dbg(common, DFS,
		"failed to allocate channel_detector for freq=%d\n", freq);
	channel_detector_exit(dpd, cd);
	return NULL;
}

/**
 * channel_detector_get() - get channel detector for given frequency
 * @param dpd instance pointer
 * @param freq frequency in MHz
 * @return pointer to channel detector on success, NULL otherwise
 *
 * Return existing channel detector for the given frequency or return a
 * newly create one.
 */
static struct channel_detector *
channel_detector_get(struct dfs_pattern_detector *dpd, u16 freq)
{
	struct channel_detector *cd;
	list_for_each_entry(cd, &dpd->channel_detectors, head) {
		if (cd->freq == freq)
			return cd;
	}
	return channel_detector_create(dpd, freq);
}

/*
 * DFS Pattern Detector
 */

/* dpd_reset(): reset all channel detectors */
static void dpd_reset(struct dfs_pattern_detector *dpd)
{
	struct channel_detector *cd;
	if (!list_empty(&dpd->channel_detectors))
		list_for_each_entry(cd, &dpd->channel_detectors, head)
			channel_detector_reset(dpd, cd);

}
static void dpd_exit(struct dfs_pattern_detector *dpd)
{
	struct channel_detector *cd, *cd0;
	if (!list_empty(&dpd->channel_detectors))
		list_for_each_entry_safe(cd, cd0, &dpd->channel_detectors, head)
			channel_detector_exit(dpd, cd);
	kfree(dpd);
}

static bool
dpd_add_pulse(struct dfs_pattern_detector *dpd, struct pulse_event *event)
{
	u32 i;
	struct channel_detector *cd;

	/*
	 * pulses received for a non-supported or un-initialized
	 * domain are treated as detected radars for fail-safety
	 */
	if (dpd->region == NL80211_DFS_UNSET)
		return true;

	cd = channel_detector_get(dpd, event->freq);
	if (cd == NULL)
		return false;

	dpd->last_pulse_ts = event->ts;
	/* reset detector on time stamp wraparound, caused by TSF reset */
	if (event->ts < dpd->last_pulse_ts)
		dpd_reset(dpd);

	/* do type individual pattern matching */
	for (i = 0; i < dpd->num_radar_types; i++) {
		struct pri_detector *pd = cd->detectors[i];
		struct pri_sequence *ps = pd->add_pulse(pd, event);
		if (ps != NULL) {
			ath_dbg(ath9k_hw_common(dpd->ah), DFS,
				"DFS: radar found on freq=%d: id=%d, pri=%d, "
				"count=%d, count_false=%d\n",
				event->freq, pd->rs->type_id,
				ps->pri, ps->count, ps->count_falses);
			channel_detector_reset(dpd, cd);
			return true;
		}
	}
	return false;
}

static bool dpd_set_domain(struct dfs_pattern_detector *dpd,
			   enum nl80211_dfs_regions region)
{
	const struct radar_types *rt;
	struct channel_detector *cd, *cd0;

	if (dpd->region == region)
		return true;

	dpd->region = NL80211_DFS_UNSET;

	rt = get_dfs_domain_radar_types(region);
	if (rt == NULL)
		return false;

	/* delete all channel detectors for previous DFS domain */
	if (!list_empty(&dpd->channel_detectors))
		list_for_each_entry_safe(cd, cd0, &dpd->channel_detectors, head)
			channel_detector_exit(dpd, cd);
	dpd->radar_spec = rt->radar_types;
	dpd->num_radar_types = rt->num_radar_types;

	dpd->region = region;
	return true;
}

static struct dfs_pattern_detector default_dpd = {
	.exit		= dpd_exit,
	.set_dfs_domain	= dpd_set_domain,
	.add_pulse	= dpd_add_pulse,
	.region		= NL80211_DFS_UNSET,
};

struct dfs_pattern_detector *
dfs_pattern_detector_init(struct ath_hw *ah, enum nl80211_dfs_regions region)
{
	struct dfs_pattern_detector *dpd;
	struct ath_common *common = ath9k_hw_common(ah);

	dpd = kmalloc(sizeof(*dpd), GFP_KERNEL);
	if (dpd == NULL)
		return NULL;

	*dpd = default_dpd;
	INIT_LIST_HEAD(&dpd->channel_detectors);

	dpd->ah = ah;
	if (dpd->set_dfs_domain(dpd, region))
		return dpd;

	ath_dbg(common, DFS,"Could not set DFS domain to %d", region);
	kfree(dpd);
	return NULL;
}
EXPORT_SYMBOL(dfs_pattern_detector_init);
Commit	Line	Data
6ee159e2 ZK	1	/*
	2	* Copyright (c) 2012 Neratec Solutions AG
	3	*
	4	* Permission to use, copy, modify, and/or distribute this software for any
	5	* purpose with or without fee is hereby granted, provided that the above
	6	* copyright notice and this permission notice appear in all copies.
	7	*
	8	* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
	9	* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
	10	* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
	11	* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
	12	* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
	13	* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
	14	* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
	15	*/
	16
	17	#include <linux/slab.h>
	18	#include <linux/export.h>
	19
	20	#include "dfs_pattern_detector.h"
	21	#include "dfs_pri_detector.h"
ca21cfde	22	#include "ath9k.h"
6ee159e2 ZK	23
	24	/*
	25	* tolerated deviation of radar time stamp in usecs on both sides
	26	* TODO: this might need to be HW-dependent
	27	*/
	28	#define PRI_TOLERANCE 16
	29
	30	/**
	31	* struct radar_types - contains array of patterns defined for one DFS domain
	32	* @domain: DFS regulatory domain
	33	* @num_radar_types: number of radar types to follow
	34	* @radar_types: radar types array
	35	*/
	36	struct radar_types {
	37	enum nl80211_dfs_regions region;
	38	u32 num_radar_types;
	39	const struct radar_detector_specs *radar_types;
	40	};
	41
	42	/* percentage on ppb threshold to trigger detection */
	43	#define MIN_PPB_THRESH 50
	44	#define PPB_THRESH(PPB) ((PPB * MIN_PPB_THRESH + 50) / 100)
	45	#define PRF2PRI(PRF) ((1000000 + PRF / 2) / PRF)
a6952287 ZK	46	/* percentage of pulse width tolerance */
	47	#define WIDTH_TOLERANCE 5
	48	#define WIDTH_LOWER(X) ((X*(100-WIDTH_TOLERANCE)+50)/100)
	49	#define WIDTH_UPPER(X) ((X*(100+WIDTH_TOLERANCE)+50)/100)
6ee159e2 ZK	50
	51	#define ETSI_PATTERN(ID, WMIN, WMAX, PMIN, PMAX, PRF, PPB) \
	52	{ \
a6952287 ZK	53	ID, WIDTH_LOWER(WMIN), WIDTH_UPPER(WMAX), \
a6952287 ZK	54	(PRF2PRI(PMAX) - PRI_TOLERANCE), \
6ee159e2 ZK	55	(PRF2PRI(PMIN) * PRF + PRI_TOLERANCE), PRF, PPB * PRF, \
	56	PPB_THRESH(PPB), PRI_TOLERANCE, \
	57	}
	58
	59	/* radar types as defined by ETSI EN-301-893 v1.5.1 */
	60	static const struct radar_detector_specs etsi_radar_ref_types_v15[] = {
	61	ETSI_PATTERN(0, 0, 1, 700, 700, 1, 18),
	62	ETSI_PATTERN(1, 0, 5, 200, 1000, 1, 10),
	63	ETSI_PATTERN(2, 0, 15, 200, 1600, 1, 15),
	64	ETSI_PATTERN(3, 0, 15, 2300, 4000, 1, 25),
	65	ETSI_PATTERN(4, 20, 30, 2000, 4000, 1, 20),
	66	ETSI_PATTERN(5, 0, 2, 300, 400, 3, 10),
	67	ETSI_PATTERN(6, 0, 2, 400, 1200, 3, 15),
	68	};
	69
	70	static const struct radar_types etsi_radar_types_v15 = {
	71	.region = NL80211_DFS_ETSI,
	72	.num_radar_types = ARRAY_SIZE(etsi_radar_ref_types_v15),
	73	.radar_types = etsi_radar_ref_types_v15,
	74	};
	75
	76	/* for now, we support ETSI radar types, FCC and JP are TODO */
	77	static const struct radar_types *dfs_domains[] = {
	78	&etsi_radar_types_v15,
	79	};
	80
	81	/**
	82	* get_dfs_domain_radar_types() - get radar types for a given DFS domain
	83	* @param domain DFS domain
	84	* @return radar_types ptr on success, NULL if DFS domain is not supported
	85	*/
	86	static const struct radar_types *
	87	get_dfs_domain_radar_types(enum nl80211_dfs_regions region)
	88	{
	89	u32 i;
	90	for (i = 0; i < ARRAY_SIZE(dfs_domains); i++) {
	91	if (dfs_domains[i]->region == region)
	92	return dfs_domains[i];
	93	}
	94	return NULL;
	95	}
	96
	97	/**
	98	* struct channel_detector - detector elements for a DFS channel
	99	* @head: list_head
	100	* @freq: frequency for this channel detector in MHz
	101	* @detectors: array of dynamically created detector elements for this freq
	102	*
	103	* Channel detectors are required to provide multi-channel DFS detection, e.g.
	104	* to support off-channel scanning. A pattern detector has a list of channels
	105	* radar pulses have been reported for in the past.
	106	*/
	107	struct channel_detector {
	108	struct list_head head;
	109	u16 freq;
	110	struct pri_detector **detectors;
	111	};
	112
	113	/* channel_detector_reset() - reset detector lines for a given channel */
	114	static void channel_detector_reset(struct dfs_pattern_detector *dpd,
	115	struct channel_detector *cd)
	116	{
	117	u32 i;
	118	if (cd == NULL)
119	return;
120	for (i = 0; i < dpd->num_radar_types; i++)
121	cd->detectors[i]->reset(cd->detectors[i], dpd->last_pulse_ts);
122	}
123
124	/* channel_detector_exit() - destructor */
125	static void channel_detector_exit(struct dfs_pattern_detector *dpd,
126	struct channel_detector *cd)
127	{
128	u32 i;
129	if (cd == NULL)
130	return;
131	list_del(&cd->head);
132	for (i = 0; i < dpd->num_radar_types; i++) {
133	struct pri_detector *de = cd->detectors[i];
134	if (de != NULL)
135	de->exit(de);
136	}
137	kfree(cd->detectors);
138	kfree(cd);
139	}
140
141	static struct channel_detector *
142	channel_detector_create(struct dfs_pattern_detector *dpd, u16 freq)
143	{
144	u32 sz, i;
145	struct channel_detector *cd;
ca21cfde	146	struct ath_common *common = ath9k_hw_common(dpd->ah);
6ee159e2	147
5d8cd3b1	148	cd = kmalloc(sizeof(*cd), GFP_ATOMIC);
6ee159e2 ZK	149	if (cd == NULL)
	150	goto fail;
	151
	152	INIT_LIST_HEAD(&cd->head);
	153	cd->freq = freq;
	154	sz = sizeof(cd->detectors) * dpd->num_radar_types;
5d8cd3b1	155	cd->detectors = kzalloc(sz, GFP_ATOMIC);
6ee159e2 ZK	156	if (cd->detectors == NULL)
	157	goto fail;
	158
	159	for (i = 0; i < dpd->num_radar_types; i++) {
	160	const struct radar_detector_specs *rs = &dpd->radar_spec[i];
	161	struct pri_detector *de = pri_detector_init(rs);
	162	if (de == NULL)
	163	goto fail;
	164	cd->detectors[i] = de;
	165	}
	166	list_add(&cd->head, &dpd->channel_detectors);
	167	return cd;
	168
	169	fail:
ca21cfde ZK	170	ath_dbg(common, DFS,
ca21cfde ZK	171	"failed to allocate channel_detector for freq=%d\n", freq);
6ee159e2 ZK	172	channel_detector_exit(dpd, cd);
	173	return NULL;
	174	}
	175
	176	/**
	177	* channel_detector_get() - get channel detector for given frequency
	178	* @param dpd instance pointer
	179	* @param freq frequency in MHz
	180	* @return pointer to channel detector on success, NULL otherwise
	181	*
	182	* Return existing channel detector for the given frequency or return a
	183	* newly create one.
	184	*/
	185	static struct channel_detector *
	186	channel_detector_get(struct dfs_pattern_detector *dpd, u16 freq)
	187	{
	188	struct channel_detector *cd;
	189	list_for_each_entry(cd, &dpd->channel_detectors, head) {
	190	if (cd->freq == freq)
	191	return cd;
	192	}
	193	return channel_detector_create(dpd, freq);
	194	}
	195
	196	/*
	197	* DFS Pattern Detector
	198	*/
	199
	200	/* dpd_reset(): reset all channel detectors */
	201	static void dpd_reset(struct dfs_pattern_detector *dpd)
	202	{
	203	struct channel_detector *cd;
	204	if (!list_empty(&dpd->channel_detectors))
	205	list_for_each_entry(cd, &dpd->channel_detectors, head)
	206	channel_detector_reset(dpd, cd);
	207
	208	}
	209	static void dpd_exit(struct dfs_pattern_detector *dpd)
	210	{
	211	struct channel_detector cd, cd0;
	212	if (!list_empty(&dpd->channel_detectors))
	213	list_for_each_entry_safe(cd, cd0, &dpd->channel_detectors, head)
	214	channel_detector_exit(dpd, cd);
	215	kfree(dpd);
	216	}
	217
	218	static bool
	219	dpd_add_pulse(struct dfs_pattern_detector dpd, struct pulse_event event)
	220	{
	221	u32 i;
6ee159e2 ZK	222	struct channel_detector *cd;
6ee159e2 ZK	223
ca21cfde ZK	224	/*
	225	* pulses received for a non-supported or un-initialized
	226	* domain are treated as detected radars for fail-safety
	227	*/
	228	if (dpd->region == NL80211_DFS_UNSET)
6ee159e2	229	return true;
6ee159e2 ZK	230
	231	cd = channel_detector_get(dpd, event->freq);
	232	if (cd == NULL)
	233	return false;
	234
6ee159e2	235	dpd->last_pulse_ts = event->ts;
ca21cfde ZK	236	/* reset detector on time stamp wraparound, caused by TSF reset */
ca21cfde ZK	237	if (event->ts < dpd->last_pulse_ts)
6ee159e2	238	dpd_reset(dpd);
ca21cfde	239
6ee159e2 ZK	240	/* do type individual pattern matching */
6ee159e2 ZK	241	for (i = 0; i < dpd->num_radar_types; i++) {
ca21cfde ZK	242	struct pri_detector *pd = cd->detectors[i];
	243	struct pri_sequence *ps = pd->add_pulse(pd, event);
	244	if (ps != NULL) {
	245	ath_dbg(ath9k_hw_common(dpd->ah), DFS,
	246	"DFS: radar found on freq=%d: id=%d, pri=%d, "
	247	"count=%d, count_false=%d\n",
	248	event->freq, pd->rs->type_id,
	249	ps->pri, ps->count, ps->count_falses);
6ee159e2 ZK	250	channel_detector_reset(dpd, cd);
	251	return true;
	252	}
	253	}
	254	return false;
	255	}
	256
	257	static bool dpd_set_domain(struct dfs_pattern_detector *dpd,
	258	enum nl80211_dfs_regions region)
	259	{
	260	const struct radar_types *rt;
	261	struct channel_detector cd, cd0;
	262
	263	if (dpd->region == region)
	264	return true;
	265
	266	dpd->region = NL80211_DFS_UNSET;
	267
	268	rt = get_dfs_domain_radar_types(region);
	269	if (rt == NULL)
	270	return false;
	271
	272	/* delete all channel detectors for previous DFS domain */
	273	if (!list_empty(&dpd->channel_detectors))
	274	list_for_each_entry_safe(cd, cd0, &dpd->channel_detectors, head)
	275	channel_detector_exit(dpd, cd);
	276	dpd->radar_spec = rt->radar_types;
	277	dpd->num_radar_types = rt->num_radar_types;
	278
	279	dpd->region = region;
	280	return true;
	281	}
	282
	283	static struct dfs_pattern_detector default_dpd = {
	284	.exit = dpd_exit,
259bcf87	285	.set_dfs_domain = dpd_set_domain,
6ee159e2 ZK	286	.add_pulse = dpd_add_pulse,
	287	.region = NL80211_DFS_UNSET,
	288	};
	289
	290	struct dfs_pattern_detector *
ca21cfde	291	dfs_pattern_detector_init(struct ath_hw *ah, enum nl80211_dfs_regions region)
6ee159e2 ZK	292	{
6ee159e2 ZK	293	struct dfs_pattern_detector *dpd;
ca21cfde	294	struct ath_common *common = ath9k_hw_common(ah);
0d2e7a5c	295
6ee159e2	296	dpd = kmalloc(sizeof(*dpd), GFP_KERNEL);
0d2e7a5c	297	if (dpd == NULL)
6ee159e2	298	return NULL;
0d2e7a5c	299
6ee159e2 ZK	300	*dpd = default_dpd;
	301	INIT_LIST_HEAD(&dpd->channel_detectors);
	302
ca21cfde	303	dpd->ah = ah;
259bcf87	304	if (dpd->set_dfs_domain(dpd, region))
6ee159e2 ZK	305	return dpd;
6ee159e2 ZK	306
ca21cfde	307	ath_dbg(common, DFS,"Could not set DFS domain to %d", region);
70bf870b	308	kfree(dpd);
6ee159e2 ZK	309	return NULL;
	310	}
	311	EXPORT_SYMBOL(dfs_pattern_detector_init);