staging: wfx: dual CTS is never necessary

Dual CTS is only necessary when sending/receiving STBC data. However,
the chip does not support STBC, so it is never necessary to enable
double CTS.

We can simplify the code.
Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Link: https://lore.kernel.org/r/20200420160311.57323-7-Jerome.Pouiller@silabs.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/wfx/hif_api_mib.h

@@ -379,12 +379,6 @@ struct hif_mib_protected_mgmt_policy {
 	u8     reserved2[3];
 } __packed;
 
-struct hif_mib_set_ht_protection {
-	u8     dual_cts_prot:1;
-	u8     reserved1:7;
-	u8     reserved2[3];
-} __packed;
-
 struct hif_mib_keep_alive_period {
 	__le16 keep_alive_period;
 	u8     reserved[2];

drivers/staging/wfx/hif_tx_mib.c

@@ -365,16 +365,6 @@ int hif_slot_time(struct wfx_vif *wvif, int val)
 			     &arg, sizeof(arg));
 }
 
-int hif_dual_cts_protection(struct wfx_vif *wvif, bool enable)
-{
-	struct hif_mib_set_ht_protection arg = {
-		.dual_cts_prot = enable,
-	};
-
-	return hif_write_mib(wvif->wdev, wvif->id, HIF_MIB_ID_SET_HT_PROTECTION,
-			     &arg, sizeof(arg));
-}
-
 int hif_wep_default_key_id(struct wfx_vif *wvif, int val)
 {
 	struct hif_mib_wep_default_key_id arg = {

drivers/staging/wfx/hif_tx_mib.h

@@ -52,7 +52,6 @@ int hif_use_multi_tx_conf(struct wfx_dev *wdev, bool enable);
 int hif_set_uapsd_info(struct wfx_vif *wvif, unsigned long val);
 int hif_erp_use_protection(struct wfx_vif *wvif, bool enable);
 int hif_slot_time(struct wfx_vif *wvif, int val);
-int hif_dual_cts_protection(struct wfx_vif *wvif, bool enable);
 int hif_wep_default_key_id(struct wfx_vif *wvif, int val);
 int hif_rts_threshold(struct wfx_vif *wvif, int val);
 

drivers/staging/wfx/sta.c

@@ -482,12 +482,6 @@ static void wfx_join_finalize(struct wfx_vif *wvif,
 	else
 		bss_params.operational_rate_set = -1;
 	rcu_read_unlock();
-	if (sta &&
-	    info->ht_operation_mode & IEEE80211_HT_OP_MODE_NON_GF_STA_PRSNT)
-		hif_dual_cts_protection(wvif, true);
-	else
-		hif_dual_cts_protection(wvif, false);
-
 	// beacon_loss_count is defined to 7 in net/mac80211/mlme.c. Let's use
 	// the same value.
 	bss_params.beacon_lost_count = 7;