static int brcmf_enable_bw40_2g(struct brcmf_cfg80211_info *cfg)
{
	struct wiphy *wiphy = cfg_to_wiphy(cfg);
	struct brcmf_if *ifp = brcmf_get_ifp(cfg->pub, 0);
	struct ieee80211_supported_band *band;
	struct brcmf_fil_bwcap_le band_bwcap;
	struct brcmf_chanspec_list *list;
	u8 *pbuf;
	u32 val;
	int err;
	struct brcmu_chan ch;
	u32 num_chan;
	int i, j;

	/* verify support for bw_cap command */
	val = WLC_BAND_5G;
	err = brcmf_fil_iovar_int_get(ifp, "bw_cap", &val);

	if (!err) {
		/* only set 2G bandwidth using bw_cap command */
		band_bwcap.band = cpu_to_le32(WLC_BAND_2G);
		band_bwcap.bw_cap = cpu_to_le32(WLC_BW_CAP_40MHZ);
		err = brcmf_fil_iovar_data_set(ifp, "bw_cap", &band_bwcap,
					       sizeof(band_bwcap));
	} else {
		brcmf_dbg(INFO, "fallback to mimo_bw_cap\n");
		val = WLC_N_BW_40ALL;
		err = brcmf_fil_iovar_int_set(ifp, "mimo_bw_cap", val);
	}

	if (!err) {
		/* update channel info in 2G band */
		pbuf = kzalloc(BRCMF_DCMD_MEDLEN, GFP_KERNEL);

		if (pbuf == NULL)
			return -ENOMEM;

		ch.band = BRCMU_CHAN_BAND_2G;
		ch.bw = BRCMU_CHAN_BW_40;
		ch.sb = BRCMU_CHAN_SB_NONE;
		ch.chnum = 0;
		cfg->d11inf.encchspec(&ch);

		/* pass encoded chanspec in query */
		*(__le16 *)pbuf = cpu_to_le16(ch.chspec);

		err = brcmf_fil_iovar_data_get(ifp, "chanspecs", pbuf,
					       BRCMF_DCMD_MEDLEN);
		if (err) {
			bphy_err(wiphy, "get chanspecs error (%d)\n", err);
			kfree(pbuf);
			return err;
		}

		band = cfg_to_wiphy(cfg)->bands[NL80211_BAND_2GHZ];
		list = (struct brcmf_chanspec_list *)pbuf;
		num_chan = le32_to_cpu(list->count);
		for (i = 0; i < num_chan; i++) {
			ch.chspec = (u16)le32_to_cpu(list->element[i]);
			cfg->d11inf.decchspec(&ch);
			if (WARN_ON(ch.band != BRCMU_CHAN_BAND_2G))
				continue;
			if (WARN_ON(ch.bw != BRCMU_CHAN_BW_40))
				continue;
			for (j = 0; j < band->n_channels; j++) {
				if (band->channels[j].hw_value == ch.control_ch_num)
					break;
			}
			if (WARN_ON(j == band->n_channels))
				continue;

			brcmf_update_bw40_channel_flag(&band->channels[j], &ch);
		}
		kfree(pbuf);
	}
	return err;
}
Unknown