mwifiex: improve readability in 11ac mcsmap to maxrate conversion

1) rename max_mcs to mcs;
2) initialize 'i' and 'nss' as 1 instead of 0 in nss lookup;
3) use GET_VHTNSSMCS(mcs_map, nss) macro;
4) use IEEE80211_VHT_MCS_* definitions instead of hard coding

Reported-by: Paul Stewart <pstew@chromium.org>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/drivers/net/wireless/mwifiex/11ac.c b/drivers/net/wireless/mwifiex/11ac.c
index f07a500..4738392 100644 (file)
--- a/drivers/net/wireless/mwifiex/11ac.c
+++ b/drivers/net/wireless/mwifiex/11ac.c
@@ -55,7 +55,7 @@ static u16
 mwifiex_convert_mcsmap_to_maxrate(struct mwifiex_private *priv,
                                  u8 bands, u16 mcs_map)
 {
-       u8 i, nss, max_mcs;
+       u8 i, nss, mcs;
        u16 max_rate = 0;
        u32 usr_vht_cap_info = 0;
        struct mwifiex_adapter *adapter = priv->adapter;
@@ -66,29 +66,29 @@ mwifiex_convert_mcsmap_to_maxrate(struct mwifiex_private *priv,
                usr_vht_cap_info = adapter->usr_dot_11ac_dev_cap_bg;
 
        /* find the max NSS supported */
-       nss = 0;
-       for (i = 0; i < 8; i++) {
-               max_mcs = (mcs_map >> (2 * i)) & 0x3;
-               if (max_mcs < 3)
+       nss = 1;
+       for (i = 1; i <= 8; i++) {
+               mcs = GET_VHTNSSMCS(mcs_map, i);
+               if (mcs < IEEE80211_VHT_MCS_NOT_SUPPORTED)
                        nss = i;
        }
-       max_mcs = (mcs_map >> (2 * nss)) & 0x3;
+       mcs = GET_VHTNSSMCS(mcs_map, nss);
 
-       /* if max_mcs is 3, nss must be 0 (SS = 1). Thus, max mcs is MCS 9 */
-       if (max_mcs >= 3)
-               max_mcs = 2;
+       /* if mcs is 3, nss must be 1 (NSS = 1). Default mcs to MCS 0~9 */
+       if (mcs == IEEE80211_VHT_MCS_NOT_SUPPORTED)
+               mcs = IEEE80211_VHT_MCS_SUPPORT_0_9;
 
        if (GET_VHTCAP_CHWDSET(usr_vht_cap_info)) {
                /* support 160 MHz */
-               max_rate = max_rate_lgi_160MHZ[nss][max_mcs];
+               max_rate = max_rate_lgi_160MHZ[nss - 1][mcs];
                if (!max_rate)
                        /* MCS9 is not supported in NSS6 */
-                       max_rate = max_rate_lgi_160MHZ[nss][max_mcs - 1];
+                       max_rate = max_rate_lgi_160MHZ[nss - 1][mcs - 1];
        } else {
-               max_rate = max_rate_lgi_80MHZ[nss][max_mcs];
+               max_rate = max_rate_lgi_80MHZ[nss - 1][mcs];
                if (!max_rate)
                        /* MCS9 is not supported in NSS3 */
-                       max_rate = max_rate_lgi_80MHZ[nss][max_mcs - 1];
+                       max_rate = max_rate_lgi_80MHZ[nss - 1][mcs - 1];
        }
 
        return max_rate;