iwlwifi: support "pure 40MHz" in RXON command

Fix the bug when using 11n "pure 40MHz" mode cause uCode
crashing by adding support for "pure 40MHz" in RX_ON command flag.
the "mode" field (bits 25:26) has value of 0-3
    0 = 20 MHz only
    1 = 40MHz only
    2 = Mixed
    3 = Reserved
Control Channel ID (bit 22) is valid only in Mixed mode.

Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

4 files changed, 72 insertions, 43 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-4965.c b/drivers/net/wireless/iwlwifi/iwl-4965.c
index 4be7bd29ef6d..7df41163ded2 100644
--- a/drivers/net/wireless/iwlwifi/iwl-4965.c
+++ b/drivers/net/wireless/iwlwifi/iwl-4965.c
@@ -293,10 +293,12 @@ restart:
         queue_work(priv->workqueue, &priv->restart);
 }
 
-static int is_fat_channel(__le32 rxon_flags)
+static bool is_fat_channel(__le32 rxon_flags)
 {
-        return (rxon_flags & RXON_FLG_CHANNEL_MODE_PURE_40_MSK) ||
-                (rxon_flags & RXON_FLG_CHANNEL_MODE_MIXED_MSK);
+        int chan_mod = le32_to_cpu(rxon_flags & RXON_FLG_CHANNEL_MODE_MSK)
+                                    >> RXON_FLG_CHANNEL_MODE_POS;
+        return ((chan_mod == CHANNEL_MODE_PURE_40) ||
+                  (chan_mod == CHANNEL_MODE_MIXED));
 }
 
 /*
@@ -1490,7 +1492,7 @@ static int iwl4965_send_tx_power(struct iwl_priv *priv)
         struct iwl4965_txpowertable_cmd cmd = { 0 };
         int ret;
         u8 band = 0;
-        u8 is_fat = 0;
+        bool is_fat = false;
         u8 ctrl_chan_high = 0;
 
         if (test_bit(STATUS_SCANNING, &priv->status)) {
@@ -1568,7 +1570,7 @@ static int iwl4965_hw_channel_switch(struct iwl_priv *priv, u16 channel)
 {
         int rc;
         u8 band = 0;
-        u8 is_fat = 0;
+        bool is_fat = false;
         u8 ctrl_chan_high = 0;
         struct iwl4965_channel_switch_cmd cmd = { 0 };
         const struct iwl_channel_info *ch_info;
diff --git a/drivers/net/wireless/iwlwifi/iwl-commands.h b/drivers/net/wireless/iwlwifi/iwl-commands.h
index 7b84d5246b36..e581dc323f0a 100644
--- a/drivers/net/wireless/iwlwifi/iwl-commands.h
+++ b/drivers/net/wireless/iwlwifi/iwl-commands.h
@@ -614,8 +614,18 @@ enum {
 
 #define RXON_FLG_CHANNEL_MODE_POS               (25)
 #define RXON_FLG_CHANNEL_MODE_MSK               cpu_to_le32(0x3 << 25)
-#define RXON_FLG_CHANNEL_MODE_PURE_40_MSK       cpu_to_le32(0x1 << 25)
-#define RXON_FLG_CHANNEL_MODE_MIXED_MSK         cpu_to_le32(0x2 << 25)
+
+/* channel mode */
+enum {
+        CHANNEL_MODE_LEGACY = 0,
+        CHANNEL_MODE_PURE_40 = 1,
+        CHANNEL_MODE_MIXED = 2,
+        CHANNEL_MODE_RESERVED = 3,
+};
+#define RXON_FLG_CHANNEL_MODE_LEGACY    cpu_to_le32(CHANNEL_MODE_LEGACY << RXON_FLG_CHANNEL_MODE_POS)
+#define RXON_FLG_CHANNEL_MODE_PURE_40   cpu_to_le32(CHANNEL_MODE_PURE_40 << RXON_FLG_CHANNEL_MODE_POS)
+#define RXON_FLG_CHANNEL_MODE_MIXED     cpu_to_le32(CHANNEL_MODE_MIXED << RXON_FLG_CHANNEL_MODE_POS)
+
 /* CTS to self (if spec allows) flag */
 #define RXON_FLG_SELF_CTS_EN                    cpu_to_le32(0x1<<30)
 
diff --git a/drivers/net/wireless/iwlwifi/iwl-core.c b/drivers/net/wireless/iwlwifi/iwl-core.c
index c7cbb2e80903..a15f7955845b 100644
--- a/drivers/net/wireless/iwlwifi/iwl-core.c
+++ b/drivers/net/wireless/iwlwifi/iwl-core.c
@@ -617,19 +617,23 @@ u8 iwl_is_fat_tx_allowed(struct iwl_priv *priv,
         struct iwl_ht_info *iwl_ht_conf = &priv->current_ht_config;
 
         if ((!iwl_ht_conf->is_ht) ||
-           (iwl_ht_conf->supported_chan_width != IWL_CHANNEL_WIDTH_40MHZ) ||
-           (iwl_ht_conf->extension_chan_offset == IEEE80211_HT_PARAM_CHA_SEC_NONE))
+            (iwl_ht_conf->supported_chan_width != IWL_CHANNEL_WIDTH_40MHZ))
                 return 0;
 
+        /* We do not check for IEEE80211_HT_CAP_SUP_WIDTH_20_40
+         * the bit will not set if it is pure 40MHz case
+         */
         if (sta_ht_inf) {
-                if ((!sta_ht_inf->ht_supported) ||
-                   (!(sta_ht_inf->cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40)))
+                if (!sta_ht_inf->ht_supported)
                         return 0;
         }
 
-        return iwl_is_channel_extension(priv, priv->band,
-                                        le16_to_cpu(priv->staging_rxon.channel),
-                                        iwl_ht_conf->extension_chan_offset);
+        if (iwl_ht_conf->ht_protection & IEEE80211_HT_OP_MODE_PROTECTION_20MHZ)
+                return 1;
+        else
+                return iwl_is_channel_extension(priv, priv->band,
+                                le16_to_cpu(priv->staging_rxon.channel),
+                                iwl_ht_conf->extension_chan_offset);
 }
 EXPORT_SYMBOL(iwl_is_fat_tx_allowed);
 
@@ -799,42 +803,51 @@ EXPORT_SYMBOL(iwl_rate_get_lowest_plcp);
 void iwl_set_rxon_ht(struct iwl_priv *priv, struct iwl_ht_info *ht_info)
 {
         struct iwl_rxon_cmd *rxon = &priv->staging_rxon;
-        u32 val;
 
         if (!ht_info->is_ht) {
-                rxon->flags &= ~(RXON_FLG_CHANNEL_MODE_MIXED_MSK |
-                        RXON_FLG_CHANNEL_MODE_PURE_40_MSK |
+                rxon->flags &= ~(RXON_FLG_CHANNEL_MODE_MSK |
                         RXON_FLG_CTRL_CHANNEL_LOC_HI_MSK |
                         RXON_FLG_FAT_PROT_MSK |
                         RXON_FLG_HT_PROT_MSK);
                 return;
         }
 
-        /* Set up channel bandwidth:  20 MHz only, or 20/40 mixed if fat ok */
-        if (iwl_is_fat_tx_allowed(priv, NULL))
-                rxon->flags |= RXON_FLG_CHANNEL_MODE_MIXED_MSK;
-        else
-                rxon->flags &= ~(RXON_FLG_CHANNEL_MODE_MIXED_MSK |
-                                 RXON_FLG_CHANNEL_MODE_PURE_40_MSK);
-
-        /* Note: control channel is opposite of extension channel */
-        switch (ht_info->extension_chan_offset) {
-        case IEEE80211_HT_PARAM_CHA_SEC_ABOVE:
-                rxon->flags &= ~(RXON_FLG_CTRL_CHANNEL_LOC_HI_MSK);
-                break;
-        case IEEE80211_HT_PARAM_CHA_SEC_BELOW:
-                rxon->flags |= RXON_FLG_CTRL_CHANNEL_LOC_HI_MSK;
-                break;
-        case IEEE80211_HT_PARAM_CHA_SEC_NONE:
-        default:
-                rxon->flags &= ~RXON_FLG_CHANNEL_MODE_MIXED_MSK;
-                break;
+        /* FIXME: if the definition of ht_protection changed, the "translation"
+         * will be needed for rxon->flags
+         */
+        rxon->flags |= cpu_to_le32(ht_info->ht_protection << RXON_FLG_HT_OPERATING_MODE_POS);
+
+        /* Set up channel bandwidth:
+         * 20 MHz only, 20/40 mixed or pure 40 if fat ok */
+        /* clear the HT channel mode before set the mode */
+        rxon->flags &= ~(RXON_FLG_CHANNEL_MODE_MSK |
+                         RXON_FLG_CTRL_CHANNEL_LOC_HI_MSK);
+        if (iwl_is_fat_tx_allowed(priv, NULL)) {
+                /* pure 40 fat */
+                if (rxon->flags & RXON_FLG_FAT_PROT_MSK)
+                        rxon->flags |= RXON_FLG_CHANNEL_MODE_PURE_40;
+                else {
+                        /* Note: control channel is opposite of extension channel */
+                        switch (ht_info->extension_chan_offset) {
+                        case IEEE80211_HT_PARAM_CHA_SEC_ABOVE:
+                                rxon->flags &= ~(RXON_FLG_CTRL_CHANNEL_LOC_HI_MSK);
+                                rxon->flags |= RXON_FLG_CHANNEL_MODE_MIXED;
+                                break;
+                        case IEEE80211_HT_PARAM_CHA_SEC_BELOW:
+                                rxon->flags |= RXON_FLG_CTRL_CHANNEL_LOC_HI_MSK;
+                                rxon->flags |= RXON_FLG_CHANNEL_MODE_MIXED;
+                                break;
+                        case IEEE80211_HT_PARAM_CHA_SEC_NONE:
+                        default:
+                                /* channel location only valid if in Mixed mode */
+                                IWL_ERR(priv, "invalid extension channel offset\n");
+                                break;
+                        }
+                }
+        } else {
+                rxon->flags |= RXON_FLG_CHANNEL_MODE_LEGACY;
         }
 
-        val = ht_info->ht_protection;
-
-        rxon->flags |= cpu_to_le32(val << RXON_FLG_HT_OPERATING_MODE_POS);
-
         if (priv->cfg->ops->hcmd->set_rxon_chain)
                 priv->cfg->ops->hcmd->set_rxon_chain(priv);
 
@@ -1122,8 +1135,9 @@ void iwl_connection_init_rx_config(struct iwl_priv *priv, int mode)
         priv->staging_rxon.cck_basic_rates =
             (IWL_CCK_RATES_MASK >> IWL_FIRST_CCK_RATE) & 0xF;
 
-        priv->staging_rxon.flags &= ~(RXON_FLG_CHANNEL_MODE_MIXED_MSK |
-                                        RXON_FLG_CHANNEL_MODE_PURE_40_MSK);
+        /* clear both MIX and PURE40 mode flag */
+        priv->staging_rxon.flags &= ~(RXON_FLG_CHANNEL_MODE_MIXED |
+                                        RXON_FLG_CHANNEL_MODE_PURE_40);
         memcpy(priv->staging_rxon.node_addr, priv->mac_addr, ETH_ALEN);
         memcpy(priv->staging_rxon.wlap_bssid_addr, priv->mac_addr, ETH_ALEN);
         priv->staging_rxon.ofdm_ht_single_stream_basic_rates = 0xff;
diff --git a/drivers/net/wireless/iwlwifi/iwl-scan.c b/drivers/net/wireless/iwlwifi/iwl-scan.c
index 065214b55895..f6d4af5c7509 100644
--- a/drivers/net/wireless/iwlwifi/iwl-scan.c
+++ b/drivers/net/wireless/iwlwifi/iwl-scan.c
@@ -586,6 +586,7 @@ static void iwl_bg_request_scan(struct work_struct *data)
         u8 rx_ant = priv->hw_params.valid_rx_ant;
         u8 rate;
         bool is_active = false;
+        int  chan_mod;
 
         conf = ieee80211_get_hw_conf(priv->hw);
 
@@ -703,7 +704,9 @@ static void iwl_bg_request_scan(struct work_struct *data)
         if (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ)) {
                 band = IEEE80211_BAND_2GHZ;
                 scan->flags = RXON_FLG_BAND_24G_MSK | RXON_FLG_AUTO_DETECT_MSK;
-                if (priv->active_rxon.flags & RXON_FLG_CHANNEL_MODE_PURE_40_MSK) {
+                chan_mod = le32_to_cpu(priv->active_rxon.flags & RXON_FLG_CHANNEL_MODE_MSK)
+                                       >> RXON_FLG_CHANNEL_MODE_POS;
+                if (chan_mod == CHANNEL_MODE_PURE_40) {
                         rate = IWL_RATE_6M_PLCP;
                 } else {
                         rate = IWL_RATE_1M_PLCP;