brcmfmac: Give priority to 5GHz band in selecting target BSS

When a BSS provides both 2.4GHz and 5GHz bands, in many cases it
makes sense to choose 5GHz. Typically a 5GHz channel is less crowded
and has less interference and therefore its performance will be
better than a crowded 2.4 GHz channel. This patch configures
'join_pref' to induce firmware to preferably select 5GHz BSS.

Reviewed-by: Arend Van Spriel <arend@broadcom.com>
Signed-off-by: Daniel Kim <dekim@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

2 files changed, 42 insertions, 0 deletions

diff --git a/drivers/net/wireless/brcm80211/brcmfmac/dhd_common.c b/drivers/net/wireless/brcm80211/brcmfmac/dhd_common.c
index 6a8983a1fb9c..ed3e32ce8c23 100644
--- a/drivers/net/wireless/brcm80211/brcmfmac/dhd_common.c
+++ b/drivers/net/wireless/brcm80211/brcmfmac/dhd_common.c
@@ -32,6 +32,9 @@
 #define BRCMF_DEFAULT_SCAN_UNASSOC_TIME 40
 #define BRCMF_DEFAULT_PACKET_FILTER     "100 0 0 0 0x01 0x00"
 
+/* boost value for RSSI_DELTA in preferred join selection */
+#define BRCMF_JOIN_PREF_RSSI_BOOST      8
+
 
 bool brcmf_c_prec_enq(struct device *dev, struct pktq *q,
                       struct sk_buff *pkt, int prec)
@@ -246,6 +249,7 @@ int brcmf_c_preinit_dcmds(struct brcmf_if *ifp)
 {
         s8 eventmask[BRCMF_EVENTING_MASK_LEN];
         u8 buf[BRCMF_DCMD_SMLEN];
+        struct brcmf_join_pref_params join_pref_params[2];
         char *ptr;
         s32 err;
 
@@ -298,6 +302,20 @@ int brcmf_c_preinit_dcmds(struct brcmf_if *ifp)
                 goto done;
         }
 
+        /* Setup join_pref to select target by RSSI(with boost on 5GHz) */
+        join_pref_params[0].type = BRCMF_JOIN_PREF_RSSI_DELTA;
+        join_pref_params[0].len = 2;
+        join_pref_params[0].rssi_gain = BRCMF_JOIN_PREF_RSSI_BOOST;
+        join_pref_params[0].band = WLC_BAND_5G;
+        join_pref_params[1].type = BRCMF_JOIN_PREF_RSSI;
+        join_pref_params[1].len = 2;
+        join_pref_params[1].rssi_gain = 0;
+        join_pref_params[1].band = 0;
+        err = brcmf_fil_iovar_data_set(ifp, "join_pref", join_pref_params,
+                                       sizeof(join_pref_params));
+        if (err)
+                brcmf_err("Set join_pref error (%d)\n", err);
+
         /* Setup event_msgs, enable E_IF */
         err = brcmf_fil_iovar_data_get(ifp, "event_msgs", eventmask,
                                        BRCMF_EVENTING_MASK_LEN);
diff --git a/drivers/net/wireless/brcm80211/brcmfmac/fwil_types.h b/drivers/net/wireless/brcm80211/brcmfmac/fwil_types.h
index 614e4888504f..2bc68a2137fc 100644
--- a/drivers/net/wireless/brcm80211/brcmfmac/fwil_types.h
+++ b/drivers/net/wireless/brcm80211/brcmfmac/fwil_types.h
@@ -53,6 +53,14 @@
 #define BRCMF_OBSS_COEX_OFF             0
 #define BRCMF_OBSS_COEX_ON              1
 
+/* join preference types for join_pref iovar */
+enum brcmf_join_pref_types {
+        BRCMF_JOIN_PREF_RSSI = 1,
+        BRCMF_JOIN_PREF_WPA,
+        BRCMF_JOIN_PREF_BAND,
+        BRCMF_JOIN_PREF_RSSI_DELTA,
+};
+
 enum brcmf_fil_p2p_if_types {
         BRCMF_FIL_P2P_IF_CLIENT,
         BRCMF_FIL_P2P_IF_GO,
@@ -282,6 +290,22 @@ struct brcmf_assoc_params_le {
         __le16 chanspec_list[1];
 };
 
+/**
+ * struct join_pref params - parameters for preferred join selection.
+ *
+ * @type: preference type (see enum brcmf_join_pref_types).
+ * @len: length of bytes following (currently always 2).
+ * @rssi_gain: signal gain for selection (only when @type is RSSI_DELTA).
+ * @band: band to which selection preference applies.
+ *      This is used if @type is BAND or RSSI_DELTA.
+ */
+struct brcmf_join_pref_params {
+        u8 type;
+        u8 len;
+        u8 rssi_gain;
+        u8 band;
+};
+
 /* used for join with or without a specific bssid and channel list */
 struct brcmf_join_params {
         struct brcmf_ssid_le ssid_le;