qtnfmac: add support for scan flush

Notify firmware to flush cache before scanning when needed.
Signed-off-by: Sergey Matyukevich <sergey.matyukevich.os@quantenna.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/quantenna/qtnfmac/commands.c

@@ -2197,6 +2197,12 @@ int qtnf_cmd_send_scan(struct qtnf_wmac *mac)
 					 scan_req->mac_addr_mask);
 	}
 
+	if (scan_req->flags & NL80211_SCAN_FLAG_FLUSH) {
+		pr_debug("MAC%u: flush cache before scan\n", mac->macid);
+
+		qtnf_cmd_skb_put_tlv_tag(cmd_skb, QTN_TLV_ID_SCAN_FLUSH);
+	}
+
 	ret = qtnf_cmd_send(mac->bus, cmd_skb);
 	if (ret)
 		goto out;

drivers/net/wireless/quantenna/qtnfmac/qlink.h

@@ -1151,6 +1151,7 @@ enum qlink_tlv_id {
 	QTN_TLV_ID_MAX_SCAN_SSIDS	= 0x0409,
 	QTN_TLV_ID_WOWLAN_CAPAB		= 0x0410,
 	QTN_TLV_ID_WOWLAN_PATTERN	= 0x0411,
+	QTN_TLV_ID_SCAN_FLUSH		= 0x0412,
 };
 
 struct qlink_tlv_hdr {

drivers/net/wireless/quantenna/qtnfmac/qlink_util.h

@@ -40,6 +40,14 @@ static inline void qtnf_cmd_skb_put_tlv_arr(struct sk_buff *skb,
 	memcpy(hdr->val, arr, arr_len);
 }
 
+static inline void qtnf_cmd_skb_put_tlv_tag(struct sk_buff *skb, u16 tlv_id)
+{
+	struct qlink_tlv_hdr *hdr = skb_put(skb, sizeof(*hdr));
+
+	hdr->type = cpu_to_le16(tlv_id);
+	hdr->len = cpu_to_le16(0);
+}
+
 static inline void qtnf_cmd_skb_put_tlv_u8(struct sk_buff *skb, u16 tlv_id,
 					   u8 value)
 {