qcacld-3.0: Fix SAP not move back to 6 GHz after STA disconnected

The API wlansap_get_valid_freq was used to get new SAP channel
when country code changed from world mode to non world mode.
In STA+SAP concurrency case, SAP may be force SCC to STA channel
or the other band's channel. And If STA is disconnected, normally
the SAP should move back to original channel frequency on 5 GHz or
6 GHz. But in current code the API wlansap_get_valid_freq will
still be invoked to get new SAP channel based on PCL after STA
is disconnected. It is not expected.

Fix by add new master_ch_list_updated flag to indicate
the master channel list has been changed from 2.4 GHz only to
2.4 GHz + 5/6 GHz and based on the flag to invoke
wlansap_get_valid_freq to get new SAP channel.
The move back to original channel has been handled by
policy_mgr_is_sap_restart_required_after_sta_disconnect.

Change-Id: I33b7a4cda3b45221b45e2aec85069477d0999d4e
CRs-Fixed: 3596546

core/sap/inc/sap_api.h

@@ -466,6 +466,7 @@ struct sap_acs_cfg {
 	uint8_t    ch_list_count;
 	uint32_t   *master_freq_list;
 	uint8_t    master_ch_list_count;
+	bool master_ch_list_updated;
 #ifdef FEATURE_WLAN_AP_AP_ACS_OPTIMIZE
 	uint8_t    skip_scan_status;
 	uint32_t    skip_scan_range1_stch;

core/sap/src/sap_module.c

@@ -2813,6 +2813,7 @@ void sap_undo_acs(struct sap_context *sap_ctx, struct sap_config *sap_cfg)
 	acs_cfg->ch_list_count = 0;
 	acs_cfg->master_ch_list_count = 0;
 	acs_cfg->acs_mode = false;
+	acs_cfg->master_ch_list_updated = false;
 	sap_ctx->num_of_channel = 0;
 	wlansap_dcs_set_vdev_wlan_interference_mitigation(sap_ctx, false);
 }
@@ -3766,6 +3767,8 @@ int wlansap_update_sap_chan_list(struct sap_config *sap_config,
 {
 	uint32_t *acs_cfg_freq_list;
 	uint32_t *master_freq_list;
+	uint32_t i;
+	bool old_acs_2g_only = true, acs_2g_only_new = true;
 
 	acs_cfg_freq_list = qdf_mem_malloc(count * sizeof(uint32_t));
 	if (!acs_cfg_freq_list)
@@ -3782,6 +3785,13 @@ int wlansap_update_sap_chan_list(struct sap_config *sap_config,
 		return -ENOMEM;
 
 	if (sap_config->acs_cfg.master_ch_list_count) {
+		for (i = 0; i < sap_config->acs_cfg.master_ch_list_count; i++)
+			if (sap_config->acs_cfg.master_freq_list &&
+			    !WLAN_REG_IS_24GHZ_CH_FREQ(
+				sap_config->acs_cfg.master_freq_list[i])) {
+				old_acs_2g_only = false;
+				break;
+			}
 		qdf_mem_free(sap_config->acs_cfg.master_freq_list);
 		sap_config->acs_cfg.master_freq_list = NULL;
 		sap_config->acs_cfg.master_ch_list_count = 0;
@@ -3794,6 +3804,24 @@ int wlansap_update_sap_chan_list(struct sap_config *sap_config,
 		     sizeof(freq_list[0]) * count);
 	sap_config->acs_cfg.master_ch_list_count = count;
 	sap_config->acs_cfg.ch_list_count = count;
+	for (i = 0; i < sap_config->acs_cfg.master_ch_list_count; i++)
+		if (sap_config->acs_cfg.master_freq_list &&
+		    !WLAN_REG_IS_24GHZ_CH_FREQ(
+				sap_config->acs_cfg.master_freq_list[i])) {
+			acs_2g_only_new = false;
+			break;
+		}
+	/* If SAP initially started on world mode, the SAP ACS master channel
+	 * list will only contain 2.4 GHz channels. When country code changed
+	 * from world mode to non world mode, the master_ch_list will
+	 * be updated by this API from userspace and the list will include
+	 * 2.4 GHz + 5/6 GHz normally. If this transition happens, we set
+	 * master_ch_list_updated flag. And later only if the flag is set,
+	 * wlansap_get_chan_band_restrict will be invoked to select new SAP
+	 * channel frequency based on PCL.
+	 */
+	sap_config->acs_cfg.master_ch_list_updated =
+			old_acs_2g_only && !acs_2g_only_new;
 	sap_dump_acs_channel(&sap_config->acs_cfg);
 
 	return 0;
@@ -3805,6 +3833,11 @@ int wlansap_update_sap_chan_list(struct sap_config *sap_config,
  * @sap_ctx: sap context
  * @freq: pointer to valid freq
  *
+ * If sap master channel list is updated from 2G only to 2G+5G/6G,
+ * this API will find new SAP channel frequency likely 5G/6G to have
+ * better performance for SAP. This happens when SAP started in
+ * world mode, later country code change to non world mode.
+ *
  * Return: None
  */
 static
@@ -3819,6 +3852,14 @@ void wlansap_get_valid_freq(struct wlan_objmgr_psoc *psoc,
 	QDF_STATUS status;
 	uint32_t pcl_len = 0;
 
+	if (!sap_ctx->acs_cfg || !sap_ctx->acs_cfg->master_ch_list_count)
+		return;
+
+	if (!sap_ctx->acs_cfg->master_ch_list_updated)
+		return;
+
+	sap_ctx->acs_cfg->master_ch_list_updated = false;
+
 	pcl_freqs =  qdf_mem_malloc(NUM_CHANNELS * sizeof(uint32_t));
 	if (!pcl_freqs)
 		return;
@@ -3957,10 +3998,9 @@ qdf_freq_t wlansap_get_chan_band_restrict(struct sap_context *sap_ctx,
 			}
 		} else {
 			wlansap_get_valid_freq(mac->psoc, sap_ctx, &freq);
-			if (!freq) {
-				sap_debug("no valid freq found");
+			if (!freq)
 				return 0;
-			}
+
 			restart_freq = freq;
 			sap_debug("restart SAP on freq %d",
 				  restart_freq);