brcmfmac: Configure keep-alive packet on suspend

When system enter suspend, there is no more wireless traffic, and
if there is no incoming data, most of the AP kick-out the client
station after few minutes because of inactivity.

The usual way to prevent this is to submit a Null function frame
periodically as a keep-alive. This is supported by brcm controllers
and can be configured via the mkeep_alive IOVAR.

Signed-off-by: Loic Poulain <loic.poulain@linaro.org>

drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c

@@ -3901,6 +3901,24 @@ static void brcmf_configure_wowl(struct brcmf_cfg80211_info *cfg,
 	cfg->wowl.active = true;
 }
 
+int brcmf_keepalive_start(struct brcmf_if *ifp, unsigned int interval)
+{
+	struct brcmf_mkeep_alive_pkt_le kalive = {0};
+	int ret = 0;
+
+	/* Configure Null function/data keepalive */
+	kalive.version = cpu_to_le16(1);
+	kalive.period_msec = cpu_to_le16(interval * MSEC_PER_SEC);
+	kalive.len_bytes = cpu_to_le16(0);
+	kalive.keep_alive_id = cpu_to_le16(0);
+
+	ret = brcmf_fil_iovar_data_set(ifp, "mkeep_alive", &kalive, sizeof(kalive));
+	if (ret)
+		brcmf_err("keep-alive packet config failed, ret=%d\n", ret);
+
+	return ret;
+}
+
 static s32 brcmf_cfg80211_suspend(struct wiphy *wiphy,
 				  struct cfg80211_wowlan *wowl)
 {
@@ -3947,6 +3965,9 @@ static s32 brcmf_cfg80211_suspend(struct wiphy *wiphy,
 	} else {
 		/* Configure WOWL paramaters */
 		brcmf_configure_wowl(cfg, ifp, wowl);
+
+		/* Prevent disassociation due to inactivity with keep-alive */
+		brcmf_keepalive_start(ifp, 30);
 	}
 
 exit:

drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwil_types.h

@@ -1052,4 +1052,23 @@ struct brcmf_gscan_config {
 	struct brcmf_gscan_bucket_config bucket[1];
 };
 
+/**
+ * struct brcmf_mkeep_alive_pkt_le - configuration data for keep-alive frame.
+ *
+ * @version: version for mkeep_alive
+ * @length: length of fixed parameters in the structure.
+ * @period_msec: keep-alive period in milliseconds.
+ * @len_bytes: size of the data.
+ * @keep_alive_id: ID  (0 - 3).
+ * @data: keep-alive frame data.
+ */
+struct brcmf_mkeep_alive_pkt_le {
+	__le16  version;
+	__le16  length;
+	__le32  period_msec;
+	__le16  len_bytes;
+	u8   keep_alive_id;
+	u8   data[0];
+} __packed;
+
 #endif /* FWIL_TYPES_H_ */