iwlwifi: use iwl_hwrate_get_mac80211_idx where appropriate

For HT packets, mac80211 expects the rate_idx to be an MCS number, which is the
lower byte of rate_n_flags.  However, iwl_hwrate_to_plcp_idx takes the MCS
number and reduces it down to the range 0-8 (6 to 60 Mbps), removing the bits
that signify multiply streams, HT40 Duplicate mode, or unequal modulation.
This version is used for various internal purposes through the driver.

Add the function iwl_hwrate_get_mac80211_idx, an alternate version which takes
the rate and the band and returns the mac80211 index (MCS, for HT packets, and
PLCP rate, for legacy packets).

Signed-off-by: Daniel C Halperin <daniel.c.halperin@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 8 insertions, 2 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-agn-rs.c b/drivers/net/wireless/iwlwifi/iwl-agn-rs.c
index 8239e5508ca..40b207aa8fe 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn-rs.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn-rs.c
@@ -878,6 +878,12 @@ static void rs_tx_status(void *priv_r, struct ieee80211_supported_band *sband,
                 rs_index -= IWL_FIRST_OFDM_RATE;
         mac_flags = info->status.rates[0].flags;
         mac_index = info->status.rates[0].idx;
+        /* For HT packets, map MCS to PLCP */
+        if (mac_flags & IEEE80211_TX_RC_MCS) {
+                mac_index &= RATE_MCS_CODE_MSK; /* Remove # of streams */
+                if (mac_index >= (IWL_RATE_9M_INDEX - IWL_FIRST_OFDM_RATE))
+                        mac_index++;
+        }
 
         if ((mac_index < 0) ||
             (tbl_type.is_SGI != !!(mac_flags & IEEE80211_TX_RC_SHORT_GI)) ||
@@ -886,8 +892,8 @@ static void rs_tx_status(void *priv_r, struct ieee80211_supported_band *sband,
             (tbl_type.ant_type != info->antenna_sel_tx) ||
             (!!(tx_rate & RATE_MCS_HT_MSK) != !!(mac_flags & IEEE80211_TX_RC_MCS)) ||
             (!!(tx_rate & RATE_MCS_GF_MSK) != !!(mac_flags & IEEE80211_TX_RC_GREEN_FIELD)) ||
-            rs_index != mac_index) {
-                IWL_DEBUG_RATE(priv, "initial rate does not match 0x%x\n", tx_rate);
+            (rs_index != mac_index)) {
+                IWL_DEBUG_RATE(priv, "initial rate %d does not match %d (0x%x)\n", mac_index, rs_index, tx_rate);
                 /* the last LQ command could failed so the LQ in ucode not
                  * the same in driver sync up
                  */