qcacld-3.0: Allow SAP(DFS) + STA(2.4) in DBS capable device

If SAP is operating in DFS channel, and STA comes up in 2.4
GHz band, then irrespective of DBS capability, SAP switches to
STA's channel for SCC.

The enhancement is to allow SAP to operate in DFS channel,
and restrict the preferred channel list for STA with 2.4 GHz
channel, if the device is DBS capable.

Change-Id: I548889265443c391d07d00951f6112983edafbcd
CRs-Fixed: 1067720

core/hdd/src/wlan_hdd_cfg80211.c

@@ -10480,16 +10480,27 @@ static bool wlan_hdd_handle_sap_sta_dfs_conc(hdd_adapter_t *adapter,
 	}
 	/*
 	 * find out by looking in to scan cache where sta is going to
-	 * connect by passing its roam_profile. if channel is 0 or DFS then
-	 * better to call pcl and find out the best channel. if channel
-	 * is non-dfs then better move SAP to STA's channel to make
-	 * scc, so we have room for 3port MCC scenario
+	 * connect by passing its roam_profile.
 	 */
 	status = cds_get_channel_from_scan_result(adapter,
 			roam_profile, &channel);
 
-	if ((QDF_STATUS_SUCCESS != status) || (0 == channel) ||
-	    CDS_IS_DFS_CH(channel))
+	/*
+	 * If the STA's channel is 2.4 GHz, then set pcl with only 2.4 GHz
+	 * channels for roaming case.
+	 */
+	if (CDS_IS_CHANNEL_24GHZ(channel)) {
+		hdd_info("sap is on dfs, new sta conn on 2.4 is allowed");
+		return true;
+	}
+
+	/*
+	 * If channel is 0 or DFS then better to call pcl and find out the
+	 * best channel. If channel is non-dfs 5 GHz then better move SAP
+	 * to STA's channel to make scc, so we have room for 3port MCC
+	 * scenario.
+	 */
+	if ((0 == channel) || CDS_IS_DFS_CH(channel))
 		channel = cds_get_nondfs_preferred_channel(CDS_SAP_MODE,
 								true);