qcacld-3.0: Start SAP on valid same band channel after country change

Currently if SAP is operating on 5GHz channel and if country change
happens to a world mode where SAP is not allowed on 5GHz channels so
SAP moves to a 2.4GHz channel and saves the current operating 5GHz
channel, now when again country change happens then SAP tries to
move to previous 5GHz channels, if SAP is not allowed on this 5GHz
channel in new country, SAP comes up on 2.4GHz channel.
Ideally SAP should come up on some other valid 5GHz channel instead
of 2.4GHz channel.
This scenario is possible for 6GHz channel as well.
To address above issue, add a fix to get first valid same band channel
if previous same band channel is not valid channel.

Change-Id: I39dc297846c838731a70cd01d696bcbd8a054970
CRs-Fixed: 3175740

components/cmn_services/policy_mgr/inc/wlan_policy_mgr_api.h

@@ -3536,6 +3536,7 @@ bool policy_mgr_sap_allowed_on_indoor_freq(struct wlan_objmgr_psoc *psoc,
  * @psoc: PSOC object information
  * @sap_vdev_id: sap vdev id.
  * @sap_ch_freq: sap channel frequency.
+ * @pref_band: Preferred band on channel is required
  *
  * This function returns an alternate channel for SAP to move to
  *
@@ -3543,7 +3544,8 @@ bool policy_mgr_sap_allowed_on_indoor_freq(struct wlan_objmgr_psoc *psoc,
  */
 uint32_t policy_mgr_get_alternate_channel_for_sap(
 	struct wlan_objmgr_psoc *psoc, uint8_t sap_vdev_id,
-	uint32_t sap_ch_freq);
+	uint32_t sap_ch_freq,
+	enum reg_wifi_band pref_band);
 
 /**
  * policy_mgr_con_mode_by_vdev_id() - Get policy mgr con mode from vdev id

components/cmn_services/policy_mgr/src/wlan_policy_mgr_action.c

@@ -2587,7 +2587,8 @@ policy_mgr_valid_sap_conc_channel_check(struct wlan_objmgr_psoc *psoc,
 	if (find_alternate) {
 		if (policy_mgr_is_hw_dbs_capable(psoc)) {
 			ch_freq = policy_mgr_get_alternate_channel_for_sap(
-						psoc, sap_vdev_id, sap_ch_freq);
+						psoc, sap_vdev_id, sap_ch_freq,
+						REG_BAND_UNKNOWN);
 			policymgr_nofl_debug("selected alternate ch %d",
 					     ch_freq);
 			if (!ch_freq) {

components/cmn_services/policy_mgr/src/wlan_policy_mgr_pcl.c

@@ -3265,12 +3265,15 @@ static uint32_t policy_mgr_get_connection_count_with_ch_freq(uint32_t ch_freq)
 
 uint32_t policy_mgr_get_alternate_channel_for_sap(
 	struct wlan_objmgr_psoc *psoc, uint8_t sap_vdev_id,
-	uint32_t sap_ch_freq)
+	uint32_t sap_ch_freq,
+	enum reg_wifi_band pref_band)
 {
 	uint32_t pcl_channels[NUM_CHANNELS];
 	uint8_t pcl_weight[NUM_CHANNELS];
 	uint32_t ch_freq = 0;
 	uint32_t pcl_len = 0;
+	uint32_t first_valid_5g_freq = 0;
+	uint32_t first_valid_6g_freq = 0;
 	struct policy_mgr_conc_connection_info info;
 	uint8_t num_cxn_del = 0;
 	struct policy_mgr_psoc_priv_obj *pm_ctx;
@@ -3320,6 +3323,18 @@ uint32_t policy_mgr_get_alternate_channel_for_sap(
 			} else if (!ch_freq) {
 				ch_freq = pcl_channels[i];
 			}
+			if (!first_valid_5g_freq &&
+			    wlan_reg_is_5ghz_ch_freq(pcl_channels[i])) {
+				first_valid_5g_freq = pcl_channels[i];
+				if (pref_band == REG_BAND_5G)
+					break;
+			}
+			if (!first_valid_6g_freq &&
+			    wlan_reg_is_6ghz_chan_freq(pcl_channels[i])) {
+				first_valid_6g_freq = pcl_channels[i];
+				if (pref_band == REG_BAND_6G)
+					break;
+			}
 		}
 	}
 
@@ -3329,6 +3344,16 @@ uint32_t policy_mgr_get_alternate_channel_for_sap(
 
 	qdf_mutex_release(&pm_ctx->qdf_conc_list_lock);
 
+	if (pref_band == REG_BAND_6G) {
+		if (first_valid_6g_freq)
+			ch_freq = first_valid_6g_freq;
+		else if (first_valid_5g_freq)
+			ch_freq = first_valid_5g_freq;
+	} else if (pref_band == REG_BAND_5G) {
+		if (first_valid_5g_freq)
+			ch_freq = first_valid_5g_freq;
+	}
+
 	return ch_freq;
 }
 

core/hdd/src/wlan_hdd_hostapd.c

@@ -5331,7 +5331,8 @@ hdd_handle_acs_2g_preferred_sap_conc(struct wlan_objmgr_psoc *psoc,
 	go_new_ch_freq =
 		policy_mgr_get_alternate_channel_for_sap(psoc,
 							 go_vdev_id,
-							 go_ch_freq);
+							 go_ch_freq,
+							 REG_BAND_UNKNOWN);
 	if (!go_new_ch_freq || WLAN_REG_IS_24GHZ_CH_FREQ(go_new_ch_freq)) {
 		hdd_err("no available 5G channel");
 		return;

core/sap/src/sap_module.c

@@ -3481,14 +3481,35 @@ qdf_freq_t wlansap_get_chan_band_restrict(struct sap_context *sap_ctx,
 		}
 		*csa_reason = CSA_REASON_BAND_RESTRICTED;
 	} else if (sap_band == REG_BAND_2G && (band & BIT(REG_BAND_5G)) &&
-		   sap_ctx->chan_freq_before_switch_band &&
-		   wlan_reg_is_enable_in_secondary_list_for_freq(mac->pdev,
+		   sap_ctx->chan_freq_before_switch_band) {
+		if (wlan_reg_is_enable_in_secondary_list_for_freq(
+				mac->pdev,
 				sap_ctx->chan_freq_before_switch_band)) {
-		restart_freq = sap_ctx->chan_freq_before_switch_band;
-		restart_ch_width = sap_ctx->chan_width_before_switch_band;
-		sap_debug("Restore chan freq: %d, width: %d",
-			  restart_freq, restart_ch_width);
-		*csa_reason = CSA_REASON_BAND_RESTRICTED;
+			restart_freq = sap_ctx->chan_freq_before_switch_band;
+			restart_ch_width = sap_ctx->chan_width_before_switch_band;
+			sap_debug("Restore chan freq: %d, width: %d",
+				  restart_freq, restart_ch_width);
+			*csa_reason = CSA_REASON_BAND_RESTRICTED;
+		} else {
+			enum reg_wifi_band pref_band;
+
+			pref_band = wlan_reg_freq_to_band(
+					sap_ctx->chan_freq_before_switch_band);
+			restart_freq =
+				policy_mgr_get_alternate_channel_for_sap(
+							mac->psoc,
+							sap_ctx->sessionId,
+							sap_ctx->chan_freq,
+							pref_band);
+			if (restart_freq) {
+				sap_debug("restart SAP on freq %d", restart_freq);
+				*csa_reason = CSA_REASON_BAND_RESTRICTED;
+			} else {
+				sap_debug("Did not get valid freq for band %d remain on same channel",
+					  pref_band);
+				return 0;
+			}
+		}
 	} else if (wlan_reg_is_disable_for_freq(mac->pdev,
 						sap_ctx->chan_freq) &&
 		   !utils_dfs_is_freq_in_nol(mac->pdev, sap_ctx->chan_freq)) {