bcmdhd.100.10.545.x/wl_roam.c - manifest_repos/dhd-driver - Git at Google

 /*
  * Linux roam cache
  *
  * Copyright (C) 1999-2019, Broadcom.
  *
  *      Unless you and Broadcom execute a separate written software license
  * agreement governing use of this software, this software is licensed to you
  * under the terms of the GNU General Public License version 2 (the "GPL"),
  * available at http://www.broadcom.com/licenses/GPLv2.php, with the
  * following added to such license:
  *
  *      As a special exception, the copyright holders of this software give you
  * permission to link this software with independent modules, and to copy and
  * distribute the resulting executable under terms of your choice, provided that
  * you also meet, for each linked independent module, the terms and conditions of
  * the license of that module.  An independent module is a module which is not
  * derived from this software.  The special exception does not apply to any
  * modifications of the software.
  *
  *      Notwithstanding the above, under no circumstances may you combine this
  * software in any way with any other Broadcom software provided under a license
  * other than the GPL, without Broadcom's express prior written consent.
  *
  *
  * <<Broadcom-WL-IPTag/Open:>>
  *
  * $Id: wl_roam.c 798173 2019-01-07 09:23:21Z $
  */

 #include <typedefs.h>
 #include <osl.h>
 #include <bcmwifi_channels.h>
 #include <wlioctl.h>
 #include <bcmutils.h>
 #ifdef WL_CFG80211
 #include <wl_cfg80211.h>
 #endif // endif
 #include <wldev_common.h>
 #include <bcmstdlib_s.h>

 #ifdef ESCAN_CHANNEL_CACHE
 #define MAX_ROAM_CACHE		200
 #define MAX_SSID_BUFSIZE	36

 #define ROAMSCAN_MODE_NORMAL	0
 #define ROAMSCAN_MODE_WES		1

 typedef struct {
 	chanspec_t chanspec;
 	int ssid_len;
 	char ssid[MAX_SSID_BUFSIZE];
 } roam_channel_cache;

 static int n_roam_cache = 0;
 static int roam_band = WLC_BAND_AUTO;
 static roam_channel_cache roam_cache[MAX_ROAM_CACHE];
 static uint band2G, band5G, band_bw;

 #ifdef ROAM_CHANNEL_CACHE
 int init_roam_cache(struct bcm_cfg80211 *cfg, int ioctl_ver)
 {
 	int err;
 	struct net_device *dev = bcmcfg_to_prmry_ndev(cfg);
 	s32 mode;

 	/* Check support in firmware */
 	err = wldev_iovar_getint(dev, "roamscan_mode", &mode);
 	if (err && (err == BCME_UNSUPPORTED)) {
 		/* If firmware doesn't support, return error. Else proceed */
 		WL_ERR(("roamscan_mode iovar failed. %d\n", err));
 		return err;
 	}

 #ifdef D11AC_IOTYPES
 	if (ioctl_ver == 1) {
 		/* legacy chanspec */
 		band2G = WL_LCHANSPEC_BAND_2G;
 		band5G = WL_LCHANSPEC_BAND_5G;
 		band_bw = WL_LCHANSPEC_BW_20 | WL_LCHANSPEC_CTL_SB_NONE;
 	} else {
 		band2G = WL_CHANSPEC_BAND_2G;
 		band5G = WL_CHANSPEC_BAND_5G;
 		band_bw = WL_CHANSPEC_BW_20;
 	}
 #else
 	band2G = WL_CHANSPEC_BAND_2G;
 	band5G = WL_CHANSPEC_BAND_5G;
 	band_bw = WL_CHANSPEC_BW_20 | WL_CHANSPEC_CTL_SB_NONE;
 #endif /* D11AC_IOTYPES */

 	n_roam_cache = 0;
 	roam_band = WLC_BAND_AUTO;

 	return 0;
 }
 #endif /* ROAM_CHANNEL_CACHE */

 #ifdef ESCAN_CHANNEL_CACHE
 void set_roam_band(int band)
 {
 	roam_band = band;
 }

 void reset_roam_cache(struct bcm_cfg80211 *cfg)
 {
 	if (!cfg->rcc_enabled) {
 		return;
 	}

 	n_roam_cache = 0;
 }

 void add_roam_cache(struct bcm_cfg80211 *cfg, wl_bss_info_t *bi)
 {
 	int i;
 	uint8 channel;
 	char chanbuf[CHANSPEC_STR_LEN];

 	if (!cfg->rcc_enabled) {
 		return;
 	}

 	if (n_roam_cache >= MAX_ROAM_CACHE)
 		return;

 	for (i = 0; i < n_roam_cache; i++) {
 		if ((roam_cache[i].ssid_len == bi->SSID_len) &&
 			(roam_cache[i].chanspec == bi->chanspec) &&
 			(memcmp(roam_cache[i].ssid, bi->SSID, bi->SSID_len) == 0)) {
 			/* identical one found, just return */
 			return;
 		}
 	}

 	roam_cache[n_roam_cache].ssid_len = bi->SSID_len;
 	channel = wf_chspec_ctlchan(bi->chanspec);
 	WL_DBG(("CHSPEC  = %s, CTL %d\n", wf_chspec_ntoa_ex(bi->chanspec, chanbuf), channel));
 	roam_cache[n_roam_cache].chanspec =
 		(channel <= CH_MAX_2G_CHANNEL ? band2G : band5G) | band_bw | channel;
 	(void)memcpy_s(roam_cache[n_roam_cache].ssid, bi->SSID_len, bi->SSID, bi->SSID_len);

 	n_roam_cache++;
 }

 static bool is_duplicated_channel(const chanspec_t *channels, int n_channels, chanspec_t new)
 {
 	int i;

 	for (i = 0; i < n_channels; i++) {
 		if (channels[i] == new)
 			return TRUE;
 	}

 	return FALSE;
 }

 int get_roam_channel_list(int target_chan,
 	chanspec_t *channels, int n_channels, const wlc_ssid_t *ssid, int ioctl_ver)
 {
 	int i, n = 1;
 	char chanbuf[CHANSPEC_STR_LEN];

 	/* first index is filled with the given target channel */
 	if (target_chan) {
 		channels[0] = (target_chan & WL_CHANSPEC_CHAN_MASK) |
 			(target_chan <= CH_MAX_2G_CHANNEL ? band2G : band5G) | band_bw;
 	} else {
 		/* If target channel is not provided, set the index to 0 */
 		n = 0;
 	}

 	WL_DBG((" %s: %03d 0x%04X\n", __FUNCTION__, target_chan, channels[0]));

 	for (i = 0; i < n_roam_cache; i++) {
 		chanspec_t ch = roam_cache[i].chanspec;
 		bool is_2G = ioctl_ver == 1 ? LCHSPEC_IS2G(ch) : CHSPEC_IS2G(ch);
 		bool is_5G = ioctl_ver == 1 ? LCHSPEC_IS5G(ch) : CHSPEC_IS5G(ch);
 		bool band_match = ((roam_band == WLC_BAND_AUTO) ||
 			((roam_band == WLC_BAND_2G) && is_2G) ||
 			((roam_band == WLC_BAND_5G) && is_5G));

 		ch = CHSPEC_CHANNEL(ch) | (is_2G ? band2G : band5G) | band_bw;
 		if ((roam_cache[i].ssid_len == ssid->SSID_len) &&
 			band_match && !is_duplicated_channel(channels, n, ch) &&
 			(memcmp(roam_cache[i].ssid, ssid->SSID, ssid->SSID_len) == 0)) {
 			/* match found, add it */
 			WL_DBG(("%s: Chanspec = %s\n", __FUNCTION__,
 				wf_chspec_ntoa_ex(ch, chanbuf)));
 			channels[n++] = ch;
 			if (n >= n_channels) {
 				WL_ERR(("Too many roam scan channels\n"));
 				return n;
 			}
 		}
 	}

 	return n;
 }
 #endif /* ESCAN_CHANNEL_CACHE */

 #ifdef ROAM_CHANNEL_CACHE
 void print_roam_cache(struct bcm_cfg80211 *cfg)
 {
 	int i;

 	if (!cfg->rcc_enabled) {
 		return;
 	}

 	WL_DBG((" %d cache\n", n_roam_cache));

 	for (i = 0; i < n_roam_cache; i++) {
 		roam_cache[i].ssid[roam_cache[i].ssid_len] = 0;
 		WL_DBG(("0x%02X %02d %s\n", roam_cache[i].chanspec,
 			roam_cache[i].ssid_len, roam_cache[i].ssid));
 	}
 }

 static void add_roamcache_channel(wl_roam_channel_list_t *channels, chanspec_t ch)
 {
 	int i;

 	if (channels->n >= MAX_ROAM_CHANNEL) /* buffer full */
 		return;

 	for (i = 0; i < channels->n; i++) {
 		if (channels->channels[i] == ch) /* already in the list */
 			return;
 	}

 	channels->channels[i] = ch;
 	channels->n++;

 	WL_DBG((" RCC: %02d 0x%04X\n",
 		ch & WL_CHANSPEC_CHAN_MASK, ch));
 }

 void update_roam_cache(struct bcm_cfg80211 *cfg, int ioctl_ver)
 {
 	int error, i, prev_channels;
 	wl_roam_channel_list_t channel_list;
 	char iobuf[WLC_IOCTL_SMLEN];
 	struct net_device *dev = bcmcfg_to_prmry_ndev(cfg);
 	wlc_ssid_t ssid;

 	if (!cfg->rcc_enabled) {
 		return;
 	}

 	if (!wl_get_drv_status(cfg, CONNECTED, dev)) {
 		WL_DBG(("Not associated\n"));
 		return;
 	}

 	/* need to read out the current cache list
 	   as the firmware may change dynamically
 	*/
 	error = wldev_iovar_getbuf(dev, "roamscan_channels", 0, 0,
 		(void *)&channel_list, sizeof(channel_list), NULL);
 	if (error) {
 		WL_ERR(("Failed to get roamscan channels, error = %d\n", error));
 		return;
 	}

 	error = wldev_get_ssid(dev, &ssid);
 	if (error) {
 		WL_ERR(("Failed to get SSID, err=%d\n", error));
 		return;
 	}

 	prev_channels = channel_list.n;
 	for (i = 0; i < n_roam_cache; i++) {
 		chanspec_t ch = roam_cache[i].chanspec;
 		bool is_2G = ioctl_ver == 1 ? LCHSPEC_IS2G(ch) : CHSPEC_IS2G(ch);
 		bool is_5G = ioctl_ver == 1 ? LCHSPEC_IS5G(ch) : CHSPEC_IS5G(ch);
 		bool band_match = ((roam_band == WLC_BAND_AUTO) ||
 			((roam_band == WLC_BAND_2G) && is_2G) ||
 			((roam_band == WLC_BAND_5G) && is_5G));

 		if ((roam_cache[i].ssid_len == ssid.SSID_len) &&
 			band_match && (memcmp(roam_cache[i].ssid, ssid.SSID, ssid.SSID_len) == 0)) {
 			/* match found, add it */
 			ch = CHSPEC_CHANNEL(ch) | (is_2G ? band2G : band5G) | band_bw;
 			add_roamcache_channel(&channel_list, ch);
 		}
 	}
 	if (prev_channels != channel_list.n) {
 		/* channel list updated */
 		error = wldev_iovar_setbuf(dev, "roamscan_channels", &channel_list,
 			sizeof(channel_list), iobuf, sizeof(iobuf), NULL);
 		if (error) {
 			WL_ERR(("Failed to update roamscan channels, error = %d\n", error));
 		}
 	}

 	WL_DBG(("%d AP, %d cache item(s), err=%d\n", n_roam_cache, channel_list.n, error));
 }

 void wl_update_roamscan_cache_by_band(struct net_device *dev, int band)
 {
 	int i, error, ioctl_ver, wes_mode;
 	wl_roam_channel_list_t chanlist_before, chanlist_after;
 	char iobuf[WLC_IOCTL_SMLEN];

 	roam_band = band;

 	error = wldev_iovar_getint(dev, "roamscan_mode", &wes_mode);
 	if (error) {
 		WL_ERR(("Failed to get roamscan mode, error = %d\n", error));
 		return;
 	}

 	ioctl_ver = wl_cfg80211_get_ioctl_version();
 	/* in case of WES mode, update channel list by band based on the cache in DHD */
 	if (wes_mode) {
 		int n = 0;
 		chanlist_before.n = n_roam_cache;

 		for (n = 0; n < n_roam_cache; n++) {
 			chanspec_t ch = roam_cache[n].chanspec;
 			bool is_2G = ioctl_ver == 1 ? LCHSPEC_IS2G(ch) : CHSPEC_IS2G(ch);
 			chanlist_before.channels[n] = CHSPEC_CHANNEL(ch) |
 				(is_2G ? band2G : band5G) | band_bw;
 		}
 	} else {
 		if (band == WLC_BAND_AUTO) {
 			return;
 		}
 		error = wldev_iovar_getbuf(dev, "roamscan_channels", 0, 0,
 				(void *)&chanlist_before, sizeof(wl_roam_channel_list_t), NULL);
 		if (error) {
 			WL_ERR(("Failed to get roamscan channels, error = %d\n", error));
 			return;
 		}
 	}
 	chanlist_after.n = 0;
 	/* filtering by the given band */
 	for (i = 0; i < chanlist_before.n; i++) {
 		chanspec_t chspec = chanlist_before.channels[i];
 		bool is_2G = ioctl_ver == 1 ? LCHSPEC_IS2G(chspec) : CHSPEC_IS2G(chspec);
 		bool is_5G = ioctl_ver == 1 ? LCHSPEC_IS5G(chspec) : CHSPEC_IS5G(chspec);
 		bool band_match = ((band == WLC_BAND_AUTO) ||
 				((band == WLC_BAND_2G) && is_2G) ||
 				((band == WLC_BAND_5G) && is_5G));
 		if (band_match) {
 			chanlist_after.channels[chanlist_after.n++] = chspec;
 		}
 	}

 	if (wes_mode) {
 		/* need to set ROAMSCAN_MODE_NORMAL to update roamscan_channels,
 		 * otherwise, it won't be updated
 		 */
 		wldev_iovar_setint(dev, "roamscan_mode", ROAMSCAN_MODE_NORMAL);

 		error = wldev_iovar_setbuf(dev, "roamscan_channels", &chanlist_after,
 				sizeof(wl_roam_channel_list_t), iobuf, sizeof(iobuf), NULL);
 		if (error) {
 			WL_ERR(("Failed to update roamscan channels, error = %d\n", error));
 		}
 		wldev_iovar_setint(dev, "roamscan_mode", ROAMSCAN_MODE_WES);
 	} else {
 		if (chanlist_before.n == chanlist_after.n) {
 			return;
 		}
 		error = wldev_iovar_setbuf(dev, "roamscan_channels", &chanlist_after,
 				sizeof(wl_roam_channel_list_t), iobuf, sizeof(iobuf), NULL);
 		if (error) {
 			WL_ERR(("Failed to update roamscan channels, error = %d\n", error));
 		}
 	}
 }
 #endif /* ROAM_CHANNEL_CACHE */
 #endif /* ESCAN_CHANNEL_CACHE */
	/*
	* Linux roam cache
	*
	* Copyright (C) 1999-2019, Broadcom.
	*
	* Unless you and Broadcom execute a separate written software license
	* agreement governing use of this software, this software is licensed to you
	* under the terms of the GNU General Public License version 2 (the "GPL"),
	* available at http://www.broadcom.com/licenses/GPLv2.php, with the
	* following added to such license:
	*
	* As a special exception, the copyright holders of this software give you
	* permission to link this software with independent modules, and to copy and
	* distribute the resulting executable under terms of your choice, provided that
	* you also meet, for each linked independent module, the terms and conditions of
	* the license of that module. An independent module is a module which is not
	* derived from this software. The special exception does not apply to any
	* modifications of the software.
	*
	* Notwithstanding the above, under no circumstances may you combine this
	* software in any way with any other Broadcom software provided under a license
	* other than the GPL, without Broadcom's express prior written consent.
	*
	*
	* <<Broadcom-WL-IPTag/Open:>>
	*
	* $Id: wl_roam.c 798173 2019-01-07 09:23:21Z $
	*/

	#include <typedefs.h>
	#include <osl.h>
	#include <bcmwifi_channels.h>
	#include <wlioctl.h>
	#include <bcmutils.h>
	#ifdef WL_CFG80211
	#include <wl_cfg80211.h>
	#endif // endif
	#include <wldev_common.h>
	#include <bcmstdlib_s.h>

	#ifdef ESCAN_CHANNEL_CACHE
	#define MAX_ROAM_CACHE 200
	#define MAX_SSID_BUFSIZE 36

	#define ROAMSCAN_MODE_NORMAL 0
	#define ROAMSCAN_MODE_WES 1

	typedef struct {
	chanspec_t chanspec;
	int ssid_len;
	char ssid[MAX_SSID_BUFSIZE];
	} roam_channel_cache;

	static int n_roam_cache = 0;
	static int roam_band = WLC_BAND_AUTO;
	static roam_channel_cache roam_cache[MAX_ROAM_CACHE];
	static uint band2G, band5G, band_bw;

	#ifdef ROAM_CHANNEL_CACHE
	int init_roam_cache(struct bcm_cfg80211 *cfg, int ioctl_ver)
	{
	int err;
	struct net_device *dev = bcmcfg_to_prmry_ndev(cfg);
	s32 mode;

	/* Check support in firmware */
	err = wldev_iovar_getint(dev, "roamscan_mode", &mode);
	if (err && (err == BCME_UNSUPPORTED)) {
	/* If firmware doesn't support, return error. Else proceed */
	WL_ERR(("roamscan_mode iovar failed. %d\n", err));
	return err;
	}

	#ifdef D11AC_IOTYPES
	if (ioctl_ver == 1) {
	/* legacy chanspec */
	band2G = WL_LCHANSPEC_BAND_2G;
	band5G = WL_LCHANSPEC_BAND_5G;
	band_bw = WL_LCHANSPEC_BW_20 \| WL_LCHANSPEC_CTL_SB_NONE;
	} else {
	band2G = WL_CHANSPEC_BAND_2G;
	band5G = WL_CHANSPEC_BAND_5G;
	band_bw = WL_CHANSPEC_BW_20;
	}
	#else
	band2G = WL_CHANSPEC_BAND_2G;
	band5G = WL_CHANSPEC_BAND_5G;
	band_bw = WL_CHANSPEC_BW_20 \| WL_CHANSPEC_CTL_SB_NONE;
	#endif /* D11AC_IOTYPES */

	n_roam_cache = 0;
	roam_band = WLC_BAND_AUTO;

	return 0;
	}
	#endif /* ROAM_CHANNEL_CACHE */

	#ifdef ESCAN_CHANNEL_CACHE
	void set_roam_band(int band)
	{
	roam_band = band;
	}

	void reset_roam_cache(struct bcm_cfg80211 *cfg)
	{
	if (!cfg->rcc_enabled) {
	return;
	}

	n_roam_cache = 0;
	}

	void add_roam_cache(struct bcm_cfg80211 cfg, wl_bss_info_t bi)
	{
	int i;
	uint8 channel;
	char chanbuf[CHANSPEC_STR_LEN];

	if (!cfg->rcc_enabled) {
	return;
	}

	if (n_roam_cache >= MAX_ROAM_CACHE)
	return;

	for (i = 0; i < n_roam_cache; i++) {
	if ((roam_cache[i].ssid_len == bi->SSID_len) &&
	(roam_cache[i].chanspec == bi->chanspec) &&
	(memcmp(roam_cache[i].ssid, bi->SSID, bi->SSID_len) == 0)) {
	/* identical one found, just return */
	return;
	}
	}

	roam_cache[n_roam_cache].ssid_len = bi->SSID_len;
	channel = wf_chspec_ctlchan(bi->chanspec);
	WL_DBG(("CHSPEC = %s, CTL %d\n", wf_chspec_ntoa_ex(bi->chanspec, chanbuf), channel));
	roam_cache[n_roam_cache].chanspec =
	(channel <= CH_MAX_2G_CHANNEL ? band2G : band5G) \| band_bw \| channel;
	(void)memcpy_s(roam_cache[n_roam_cache].ssid, bi->SSID_len, bi->SSID, bi->SSID_len);

	n_roam_cache++;
	}

	static bool is_duplicated_channel(const chanspec_t *channels, int n_channels, chanspec_t new)
	{
	int i;

	for (i = 0; i < n_channels; i++) {
	if (channels[i] == new)
	return TRUE;
	}

	return FALSE;
	}

	int get_roam_channel_list(int target_chan,
	chanspec_t channels, int n_channels, const wlc_ssid_t ssid, int ioctl_ver)
	{
	int i, n = 1;
	char chanbuf[CHANSPEC_STR_LEN];

	/* first index is filled with the given target channel */
	if (target_chan) {
	channels[0] = (target_chan & WL_CHANSPEC_CHAN_MASK) \|
	(target_chan <= CH_MAX_2G_CHANNEL ? band2G : band5G) \| band_bw;
	} else {
	/* If target channel is not provided, set the index to 0 */
	n = 0;
	}

	WL_DBG((" %s: %03d 0x%04X\n", __FUNCTION__, target_chan, channels[0]));

	for (i = 0; i < n_roam_cache; i++) {
	chanspec_t ch = roam_cache[i].chanspec;
	bool is_2G = ioctl_ver == 1 ? LCHSPEC_IS2G(ch) : CHSPEC_IS2G(ch);
	bool is_5G = ioctl_ver == 1 ? LCHSPEC_IS5G(ch) : CHSPEC_IS5G(ch);
	bool band_match = ((roam_band == WLC_BAND_AUTO) \|\|
	((roam_band == WLC_BAND_2G) && is_2G) \|\|
	((roam_band == WLC_BAND_5G) && is_5G));

	ch = CHSPEC_CHANNEL(ch) \| (is_2G ? band2G : band5G) \| band_bw;
	if ((roam_cache[i].ssid_len == ssid->SSID_len) &&
	band_match && !is_duplicated_channel(channels, n, ch) &&
	(memcmp(roam_cache[i].ssid, ssid->SSID, ssid->SSID_len) == 0)) {
	/* match found, add it */
	WL_DBG(("%s: Chanspec = %s\n", __FUNCTION__,
	wf_chspec_ntoa_ex(ch, chanbuf)));
	channels[n++] = ch;
	if (n >= n_channels) {
	WL_ERR(("Too many roam scan channels\n"));
	return n;
	}
	}
	}

	return n;
	}
	#endif /* ESCAN_CHANNEL_CACHE */

	#ifdef ROAM_CHANNEL_CACHE
	void print_roam_cache(struct bcm_cfg80211 *cfg)
	{
	int i;

	if (!cfg->rcc_enabled) {
	return;
	}

	WL_DBG((" %d cache\n", n_roam_cache));

	for (i = 0; i < n_roam_cache; i++) {
	roam_cache[i].ssid[roam_cache[i].ssid_len] = 0;
	WL_DBG(("0x%02X %02d %s\n", roam_cache[i].chanspec,
	roam_cache[i].ssid_len, roam_cache[i].ssid));
	}
	}

	static void add_roamcache_channel(wl_roam_channel_list_t *channels, chanspec_t ch)
	{
	int i;

	if (channels->n >= MAX_ROAM_CHANNEL) /* buffer full */
	return;

	for (i = 0; i < channels->n; i++) {
	if (channels->channels[i] == ch) /* already in the list */
	return;
	}

	channels->channels[i] = ch;
	channels->n++;

	WL_DBG((" RCC: %02d 0x%04X\n",
	ch & WL_CHANSPEC_CHAN_MASK, ch));
	}

	void update_roam_cache(struct bcm_cfg80211 *cfg, int ioctl_ver)
	{
	int error, i, prev_channels;
	wl_roam_channel_list_t channel_list;
	char iobuf[WLC_IOCTL_SMLEN];
	struct net_device *dev = bcmcfg_to_prmry_ndev(cfg);
	wlc_ssid_t ssid;

	if (!cfg->rcc_enabled) {
	return;
	}

	if (!wl_get_drv_status(cfg, CONNECTED, dev)) {
	WL_DBG(("Not associated\n"));
	return;
	}

	/* need to read out the current cache list
	as the firmware may change dynamically
	*/
	error = wldev_iovar_getbuf(dev, "roamscan_channels", 0, 0,
	(void *)&channel_list, sizeof(channel_list), NULL);
	if (error) {
	WL_ERR(("Failed to get roamscan channels, error = %d\n", error));
	return;
	}

	error = wldev_get_ssid(dev, &ssid);
	if (error) {
	WL_ERR(("Failed to get SSID, err=%d\n", error));
	return;
	}

	prev_channels = channel_list.n;
	for (i = 0; i < n_roam_cache; i++) {
	chanspec_t ch = roam_cache[i].chanspec;
	bool is_2G = ioctl_ver == 1 ? LCHSPEC_IS2G(ch) : CHSPEC_IS2G(ch);
	bool is_5G = ioctl_ver == 1 ? LCHSPEC_IS5G(ch) : CHSPEC_IS5G(ch);
	bool band_match = ((roam_band == WLC_BAND_AUTO) \|\|
	((roam_band == WLC_BAND_2G) && is_2G) \|\|
	((roam_band == WLC_BAND_5G) && is_5G));

	if ((roam_cache[i].ssid_len == ssid.SSID_len) &&
	band_match && (memcmp(roam_cache[i].ssid, ssid.SSID, ssid.SSID_len) == 0)) {
	/* match found, add it */
	ch = CHSPEC_CHANNEL(ch) \| (is_2G ? band2G : band5G) \| band_bw;
	add_roamcache_channel(&channel_list, ch);
	}
	}
	if (prev_channels != channel_list.n) {
	/* channel list updated */
	error = wldev_iovar_setbuf(dev, "roamscan_channels", &channel_list,
	sizeof(channel_list), iobuf, sizeof(iobuf), NULL);
	if (error) {
	WL_ERR(("Failed to update roamscan channels, error = %d\n", error));
	}
	}

	WL_DBG(("%d AP, %d cache item(s), err=%d\n", n_roam_cache, channel_list.n, error));
	}

	void wl_update_roamscan_cache_by_band(struct net_device *dev, int band)
	{
	int i, error, ioctl_ver, wes_mode;
	wl_roam_channel_list_t chanlist_before, chanlist_after;
	char iobuf[WLC_IOCTL_SMLEN];

	roam_band = band;

	error = wldev_iovar_getint(dev, "roamscan_mode", &wes_mode);
	if (error) {
	WL_ERR(("Failed to get roamscan mode, error = %d\n", error));
	return;
	}

	ioctl_ver = wl_cfg80211_get_ioctl_version();
	/* in case of WES mode, update channel list by band based on the cache in DHD */
	if (wes_mode) {
	int n = 0;
	chanlist_before.n = n_roam_cache;

	for (n = 0; n < n_roam_cache; n++) {
	chanspec_t ch = roam_cache[n].chanspec;
	bool is_2G = ioctl_ver == 1 ? LCHSPEC_IS2G(ch) : CHSPEC_IS2G(ch);
	chanlist_before.channels[n] = CHSPEC_CHANNEL(ch) \|
	(is_2G ? band2G : band5G) \| band_bw;
	}
	} else {
	if (band == WLC_BAND_AUTO) {
	return;
	}
	error = wldev_iovar_getbuf(dev, "roamscan_channels", 0, 0,
	(void *)&chanlist_before, sizeof(wl_roam_channel_list_t), NULL);
	if (error) {
	WL_ERR(("Failed to get roamscan channels, error = %d\n", error));
	return;
	}
	}
	chanlist_after.n = 0;
	/* filtering by the given band */
	for (i = 0; i < chanlist_before.n; i++) {
	chanspec_t chspec = chanlist_before.channels[i];
	bool is_2G = ioctl_ver == 1 ? LCHSPEC_IS2G(chspec) : CHSPEC_IS2G(chspec);
	bool is_5G = ioctl_ver == 1 ? LCHSPEC_IS5G(chspec) : CHSPEC_IS5G(chspec);
	bool band_match = ((band == WLC_BAND_AUTO) \|\|
	((band == WLC_BAND_2G) && is_2G) \|\|
	((band == WLC_BAND_5G) && is_5G));
	if (band_match) {
	chanlist_after.channels[chanlist_after.n++] = chspec;
	}
	}

	if (wes_mode) {
	/* need to set ROAMSCAN_MODE_NORMAL to update roamscan_channels,
	* otherwise, it won't be updated
	*/
	wldev_iovar_setint(dev, "roamscan_mode", ROAMSCAN_MODE_NORMAL);

	error = wldev_iovar_setbuf(dev, "roamscan_channels", &chanlist_after,
	sizeof(wl_roam_channel_list_t), iobuf, sizeof(iobuf), NULL);
	if (error) {
	WL_ERR(("Failed to update roamscan channels, error = %d\n", error));
	}
	wldev_iovar_setint(dev, "roamscan_mode", ROAMSCAN_MODE_WES);
	} else {
	if (chanlist_before.n == chanlist_after.n) {
	return;
	}
	error = wldev_iovar_setbuf(dev, "roamscan_channels", &chanlist_after,
	sizeof(wl_roam_channel_list_t), iobuf, sizeof(iobuf), NULL);
	if (error) {
	WL_ERR(("Failed to update roamscan channels, error = %d\n", error));
	}
	}
	}
	#endif /* ROAM_CHANNEL_CACHE */
	#endif /* ESCAN_CHANNEL_CACHE */