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Commit 93bc8ac4 authored by Johannes Berg's avatar Johannes Berg
Browse files

cfg80211: fix ieee80211_get_vht_max_nss() 



Fix two bugs in ieee80211_get_vht_max_nss():
 * the spec says we should round down
   (reported by Nissim)
 * there's a double condition, the first one is wrong,
   supp_width == 0 / ext_nss_bw == 2 is valid in 80+80
   (found by smatch)

Fixes: b0aa75f0 ("ieee80211: add new VHT capability fields/parsing")
Reported-by: default avatarNissim Bendanan <nissimx.bendanan@intel.com>
Signed-off-by: default avatarLuca Coelho <luciano.coelho@intel.com>
Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent efc38dd7

net/wireless/util.c

+7 −8
Original line number Diff line number Diff line
@@ -2013,33 +2013,32 @@ int ieee80211_get_vht_max_nss(struct ieee80211_vht_cap *cap, 
	case IEEE80211_VHT_CHANWIDTH_160MHZ:

		if (supp_width == 0 &&

		    (ext_nss_bw == 1 || ext_nss_bw == 2))

			return DIV_ROUND_UP(max_vht_nss, 2);

			return max_vht_nss / 2;

		if (supp_width == 0 &&

		    ext_nss_bw == 3)

			return DIV_ROUND_UP(3 * max_vht_nss, 4);

			return (3 * max_vht_nss) / 4;

		if (supp_width == 1 &&

		    ext_nss_bw == 3)

			return 2 * max_vht_nss;

		break;

	case IEEE80211_VHT_CHANWIDTH_80P80MHZ:

		if (supp_width == 0 &&

		    (ext_nss_bw == 1 || ext_nss_bw == 2))

		if (supp_width == 0 && ext_nss_bw == 1)

			return 0; /* not possible */

		if (supp_width == 0 &&

		    ext_nss_bw == 2)

			return DIV_ROUND_UP(max_vht_nss, 2);

			return max_vht_nss / 2;

		if (supp_width == 0 &&

		    ext_nss_bw == 3)

			return DIV_ROUND_UP(3 * max_vht_nss, 4);

			return (3 * max_vht_nss) / 4;

		if (supp_width == 1 &&

		    ext_nss_bw == 0)

			return 0; /* not possible */

		if (supp_width == 1 &&

		    ext_nss_bw == 1)

			return DIV_ROUND_UP(max_vht_nss, 2);

			return max_vht_nss / 2;

		if (supp_width == 1 &&

		    ext_nss_bw == 2)

			return DIV_ROUND_UP(3 * max_vht_nss, 4);

			return (3 * max_vht_nss) / 4;

		break;

	}