iwlwifi: mvm: check TLV flag before trying to use hotspot firmware commands

Older firmwares do not provide support for the HOT_SPOT_CMD command.
Check for the appropriate TLV flag that declares hotspot support in
the firmware to prevent a firmware assertion failure that can be
triggered from the userspace,

Cc: stable@vger.kernel.org [3.17+]
Signed-off-by: Luciano Coelho <luciano.coelho@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

drivers/net/wireless/iwlwifi/iwl-fw.h

@@ -155,6 +155,7 @@ enum iwl_ucode_tlv_api {
  * @IWL_UCODE_TLV_CAPA_QUIET_PERIOD_SUPPORT: supports Quiet Period requests
  * @IWL_UCODE_TLV_CAPA_DQA_SUPPORT: supports dynamic queue allocation (DQA),
  *	which also implies support for the scheduler configuration command
+ * @IWL_UCODE_TLV_CAPA_HOTSPOT_SUPPORT: supports Hot Spot Command
  */
 enum iwl_ucode_tlv_capa {
 	IWL_UCODE_TLV_CAPA_D0I3_SUPPORT			= BIT(0),
@@ -163,6 +164,7 @@ enum iwl_ucode_tlv_capa {
 	IWL_UCODE_TLV_CAPA_WFA_TPC_REP_IE_SUPPORT	= BIT(10),
 	IWL_UCODE_TLV_CAPA_QUIET_PERIOD_SUPPORT		= BIT(11),
 	IWL_UCODE_TLV_CAPA_DQA_SUPPORT			= BIT(12),
+	IWL_UCODE_TLV_CAPA_HOTSPOT_SUPPORT		= BIT(18),
 };
 
 /* The default calibrate table size if not specified by firmware file */

drivers/net/wireless/iwlwifi/mvm/mac80211.c

@@ -2448,10 +2448,16 @@ static int iwl_mvm_roc(struct ieee80211_hw *hw,
 
 	switch (vif->type) {
 	case NL80211_IFTYPE_STATION:
+		if (mvm->fw->ucode_capa.capa[0] &
+		    IWL_UCODE_TLV_CAPA_HOTSPOT_SUPPORT) {
 			/* Use aux roc framework (HS20) */
 			ret = iwl_mvm_send_aux_roc_cmd(mvm, channel,
 						       vif, duration);
 			goto out_unlock;
+		}
+		IWL_ERR(mvm, "hotspot not supported\n");
+		ret = -EINVAL;
+		goto out_unlock;
 	case NL80211_IFTYPE_P2P_DEVICE:
 		/* handle below */
 		break;