qcacld-3.0: Use policy mgr safe ch list in ACS

Currently the driver uses a global safe channel
list, and also keeps another safe channel list in
policy mgr which results in duplicate copies
of the same thing.
Also there are many possible issues which are seen
if the global list implementation is used.

Issue 1:-
The global unsafe ch list is maintained for each
channel and is updated as part of ACS scan cb.
So if a user does ACS again and again ( SAP on off)
then the result of unsafe channels of the previous
ACS request would be updated as part of the ACS cb
of the new ACS scan request.
In the function of sap_get_freq_list, the driver
filters out the channels which are unsafe, and the
same channels are not chosen as the best channel for
SAP operation.
Now the filtration of the channels would happen
according to the previous ACS request, and the driver
would remove the channels from the ACS scan list.
But those channels were unsafe when the previous ACS
happened, and may not be unsafe now, and can be used
to turn on the SAP (can be chosen as the best channel)

Issue 2:-
If the channels are truly unsafe, then the driver
filters out the channel in the function sap_get_freq_list,
and do not chose them for the SAP.
It may happen that the channel list that the driver
preferred as part of do acs becomes unsafe, and the
channels that were unsafe at the time of do acs becomes
safe while the driver was scanning the ACS channels to
find other APs.
Now since the channels that were unsafe at the time of
ACS req are safe now, they could have been chosen as the
best channel but they were not scanned, so the ACS channel
weight of these channels would remain maximum, and they
would be sorted at last of the sorted list.
Also the channels that were as part of the ACS channels list
became unsafe, hence the driver would also assign maximum
weight to them, and they would too become unusable channels.
This would result in all channels having the same weight that
is maximum weight, and so the sorting algorithm does not have
to sort any channel now since all of the weights are same.
The first channel in the sorted list would be channel number
1 of 2.4Ghz, and would get chosen, but this may not be
correct if the HW mode is 5ghz only.

Fix:-
Safe and unsafe channels can be checked by using
policy mgr safe channel list too, so it is better
to keep just one unsafe channel list.
The driver would not filter out the unsafe channels
for ACS scan, and would filter out the unsafe channels
as part of the ACS scan done callback.

Change-Id: Ief236db9e73864e5cb2d290a8106799f9e80f82d
CRs-Fixed: 2530241

core/sap/inc/sap_api.h

@@ -632,14 +632,6 @@ typedef struct tagSapStruct {
 	bool enable_dfs_phy_error_logs;
 } tSapStruct, *tpSapStruct;
 
-#ifdef FEATURE_WLAN_CH_AVOID
-/* Store channel safety information */
-typedef struct {
-	uint16_t channelNumber;
-	bool isSafe;
-} sapSafeChannelType;
-#endif /* FEATURE_WLAN_CH_AVOID */
-
 /**
  * struct sap_context - per-BSS Context for SAP
  *

core/sap/src/sap_api_link_cntl.c

@@ -232,6 +232,45 @@ wlansap_calculate_chan_from_scan_result(mac_handle_t mac_handle,
 	return oper_channel;
 }
 
+static void
+wlansap_filter_unsafe_ch(struct wlan_objmgr_psoc *psoc,
+			 struct sap_context *sap_ctx)
+{
+	uint16_t i;
+	uint16_t num_safe_ch = 0;
+
+	/*
+	 * There are two channel list, one acs cfg channel list, and one
+	 * sap_ctx->freq_list, the unsafe channels for acs cfg is updated here
+	 * and the sap_ctx->freq list would be handled in sap_chan_sel_init
+	 * which would consider more params other than unsafe channels.
+	 * So the two lists now would be in sync. But in case the ACS weight
+	 * calculation does not get through due to no scan result or no chan
+	 * selected, or any other reason, the default channel is chosen which
+	 * would contain the channels in acs cfg. Now since the scan takes time
+	 * there could be channels present in acs cfg that could become unsafe
+	 * in the mean time, so it is better to filter out those channels from
+	 * the acs channel list before chosing one of them as a default channel
+	 */
+	for (i = 0; i < sap_ctx->acs_cfg->ch_list_count; i++) {
+		if (!policy_mgr_is_safe_channel(psoc,
+					        sap_ctx->acs_cfg->ch_list[i])) {
+			sap_debug("unsafe ch %d removed from acs list",
+				  sap_ctx->acs_cfg->ch_list[i]);
+			continue;
+		}
+		/* Add only safe channels to the acs cfg ch list */
+		sap_ctx->acs_cfg->ch_list[num_safe_ch++] =
+						sap_ctx->acs_cfg->ch_list[i];
+	}
+
+	sap_debug("Updated ACS ch list len %d", num_safe_ch);
+	sap_ctx->acs_cfg->ch_list_count = num_safe_ch;
+
+	for (i = 0; i < num_safe_ch; i++)
+		sap_debug("Ch %d", sap_ctx->acs_cfg->ch_list[i]);
+}
+
 QDF_STATUS wlansap_pre_start_bss_acs_scan_callback(mac_handle_t mac_handle,
 						   struct sap_context *sap_ctx,
 						   uint8_t sessionid,
@@ -243,6 +282,20 @@ QDF_STATUS wlansap_pre_start_bss_acs_scan_callback(mac_handle_t mac_handle,
 
 	host_log_acs_scan_done(acs_scan_done_status_str(scan_status),
 			  sessionid, scanid);
+
+	/* This has to be done before the ACS selects default channel */
+	wlansap_filter_unsafe_ch(mac_ctx->psoc, sap_ctx);
+
+	if (!sap_ctx->acs_cfg->ch_list_count) {
+		sap_err("No channel left for SAP operation, hotspot fail");
+		sap_ctx->chan_freq = SAP_CHANNEL_NOT_SELECTED;
+		sap_ctx->acs_cfg->pri_ch = SAP_CHANNEL_NOT_SELECTED;
+		sap_config_acs_result(mac_handle, sap_ctx, 0);
+		sap_ctx->sap_state = eSAP_ACS_CHANNEL_SELECTED;
+		sap_ctx->sap_status = eSAP_START_BSS_CHANNEL_NOT_SELECTED;
+		goto close_session;
+
+	}
 	if (eCSR_SCAN_SUCCESS != scan_status) {
 		QDF_TRACE(QDF_MODULE_ID_SAP, QDF_TRACE_LEVEL_ERROR,
 			FL("CSR scan_status = eCSR_SCAN_ABORT/FAILURE (%d), choose default channel"),

core/sap/src/sap_ch_select.c

@@ -118,52 +118,6 @@
 #define ACS_WEIGHT_SOFTAP_TX_POWER_THROUGHPUT_CFG(weights) \
 	(((weights) & 0xf00000) >> 20)
 
-#ifdef FEATURE_WLAN_CH_AVOID
-sapSafeChannelType safe_channels[NUM_CHANNELS] = {
-	{1, true},
-	{2, true},
-	{3, true},
-	{4, true},
-	{5, true},
-	{6, true},
-	{7, true},
-	{8, true},
-	{9, true},
-	{10, true},
-	{11, true},
-	{12, true},
-	{13, true},
-	{14, true},
-	{36, true},
-	{40, true},
-	{44, true},
-	{48, true},
-	{52, true},
-	{56, true},
-	{60, true},
-	{64, true},
-	{100, true},
-	{104, true},
-	{108, true},
-	{112, true},
-	{116, true},
-	{120, true},
-	{124, true},
-	{128, true},
-	{132, true},
-	{136, true},
-	{140, true},
-	{144, true},
-	{149, true},
-	{153, true},
-	{157, true},
-	{161, true},
-	{165, true},
-	{169, true},
-	{173, true},
-};
-#endif
-
 typedef struct {
 	uint16_t chStartNum;
 	uint32_t weight;
@@ -399,93 +353,6 @@ static void sap_process_avoid_ie(mac_handle_t mac_handle,
 }
 #endif /* FEATURE_AP_MCC_CH_AVOIDANCE */
 
-#ifdef FEATURE_WLAN_CH_AVOID
-/*==========================================================================
-   FUNCTION    sap_update_unsafe_channel_list
-
-   DESCRIPTION
-    Function  Undate unsafe channel list table
-
-   DEPENDENCIES
-    NA.
-
-   IN
-    SapContext pointer
-
-   RETURN VALUE
-    NULL
-   ============================================================================*/
-static void sap_update_unsafe_channel_list(mac_handle_t mac_handle,
-					   struct sap_context *sap_ctx)
-{
-	uint16_t i, j;
-	uint16_t unsafe_channel_list[NUM_CHANNELS];
-	uint16_t unsafe_channel_count = 0;
-	struct mac_context *mac_ctx = NULL;
-
-	qdf_device_t qdf_ctx = cds_get_context(QDF_MODULE_ID_QDF_DEVICE);
-
-	if (!qdf_ctx) {
-		QDF_TRACE(QDF_MODULE_ID_SAP, QDF_TRACE_LEVEL_FATAL,
-			  "qdf_ctx is NULL");
-		return;
-	}
-	mac_ctx = MAC_CONTEXT(mac_handle);
-
-	/* Flush, default set all channel safe */
-	for (i = 0; i < NUM_CHANNELS; i++) {
-		safe_channels[i].isSafe = true;
-	}
-
-	/* Try to find unsafe channel */
-#if defined(FEATURE_WLAN_STA_AP_MODE_DFS_DISABLE)
-	for (i = 0; i < NUM_CHANNELS; i++) {
-		if (sap_ctx->dfs_ch_disable == true) {
-			if (wlan_reg_is_dfs_ch(mac_ctx->pdev,
-					safe_channels[i].channelNumber)) {
-				safe_channels[i].isSafe = false;
-				QDF_TRACE(QDF_MODULE_ID_SAP,
-					QDF_TRACE_LEVEL_INFO_HIGH,
-					"%s: DFS Ch %d is not safe in"
-					" Concurrent mode",
-					__func__,
-					safe_channels[i].channelNumber);
-			}
-		}
-	}
-#endif
-	pld_get_wlan_unsafe_channel(qdf_ctx->dev,
-				    unsafe_channel_list,
-				     &unsafe_channel_count,
-				     sizeof(unsafe_channel_list));
-
-	unsafe_channel_count = QDF_MIN(unsafe_channel_count,
-				       (uint16_t)NUM_CHANNELS);
-
-	for (i = 0; i < unsafe_channel_count; i++) {
-		for (j = 0; j < NUM_CHANNELS; j++) {
-			if (safe_channels[j].channelNumber ==
-			    unsafe_channel_list[i]) {
-				/* Found unsafe channel, update it */
-				safe_channels[j].isSafe = false;
-				QDF_TRACE(QDF_MODULE_ID_SAP,
-					  QDF_TRACE_LEVEL_ERROR,
-					  FL("CH %d is not safe"),
-					  unsafe_channel_list[i]);
-				break;
-			}
-		}
-	}
-
-	return;
-}
-#else
-static void sap_update_unsafe_channel_list(mac_handle_t mac_handle,
-					   struct sap_context *sap_ctx)
-{
-}
-#endif /* FEATURE_WLAN_CH_AVOID */
-
 /**
  * sap_channel_in_acs_channel_list() - check if channel in acs channel list
  * @channel_num: channel to check
@@ -593,9 +460,6 @@ static bool sap_chan_sel_init(mac_handle_t mac_handle,
 	uint16_t channelnum = 0;
 	struct mac_context *mac = MAC_CONTEXT(mac_handle);
 	bool chSafe = true;
-#ifdef FEATURE_WLAN_CH_AVOID
-	uint16_t i;
-#endif
 	bool include_dfs_ch = true;
 	uint8_t chan_num;
 	bool sta_sap_scc_on_dfs_chan =
@@ -666,19 +530,8 @@ static bool sap_chan_sel_init(mac_handle_t mac_handle,
 			}
 		}
 
-#ifdef FEATURE_WLAN_CH_AVOID
-		for (i = 0; i < NUM_CHANNELS; i++) {
-			if ((safe_channels[i].channelNumber == channel) &&
-			    (false == safe_channels[i].isSafe)) {
-				QDF_TRACE(QDF_MODULE_ID_SAP,
-					  QDF_TRACE_LEVEL_INFO_HIGH,
-					  "In %s, Ch %d is not safe", __func__,
-					  channel);
-				chSafe = false;
-				break;
-			}
-		}
-#endif /* FEATURE_WLAN_CH_AVOID */
+		if (!policy_mgr_is_safe_channel(mac->psoc, channel))
+			chSafe = false;
 
 		/* OFDM rates are not supported on channel 14 */
 		if (channel == 14 &&
@@ -2561,8 +2414,6 @@ uint8_t sap_select_channel(mac_handle_t mac_handle,
 	QDF_TRACE(QDF_MODULE_ID_SAP, QDF_TRACE_LEVEL_INFO_HIGH,
 		  "In %s, Running SAP Ch Select", __func__);
 
-	sap_update_unsafe_channel_list(mac_handle, sap_ctx);
-
 	/*
 	 * If ACS weight is not enabled on noise_floor/channel_free/tx_power,
 	 * then skip acs process if no bss found.

core/sap/src/sap_fsm.c

@@ -73,10 +73,6 @@
 /*----------------------------------------------------------------------------
  *  External declarations for global context
  * -------------------------------------------------------------------------*/
-#ifdef FEATURE_WLAN_CH_AVOID
-extern sapSafeChannelType safe_channels[];
-#endif /* FEATURE_WLAN_CH_AVOID */
-
 /*----------------------------------------------------------------------------
  * Static Variable Definitions
  * -------------------------------------------------------------------------*/
@@ -676,11 +672,31 @@ sap_chan_bond_dfs_sub_chan(struct sap_context *sap_context,
 
 uint8_t sap_select_default_oper_chan(struct sap_acs_cfg *acs_cfg)
 {
-	if (!acs_cfg || !acs_cfg->ch_list)
+	uint16_t i;
+
+	if (!acs_cfg || !acs_cfg->ch_list || !acs_cfg->ch_list_count)
 		return 0;
 
+	/*
+	 * There could be both 2.4Ghz and 5ghz channels present in the list
+	 * based upon the Hw mode received from hostapd, it is always better
+	 * to chose a default 5ghz operating channel than 2.4ghz, as it can
+	 * provide a better throughput, latency than 2.4ghz. Also 40 Mhz is
+	 * rare in 2.4ghz band, so 5ghz should be preferred. If we get a 5Ghz
+	 * chan in the acs cfg ch list , we should go for that first else the
+	 * default channel can be 2.4ghz.
+	 */
+
+	for (i = 0; i < acs_cfg->ch_list_count; i++) {
+		if (WLAN_CHAN_IS_5GHZ(acs_cfg->ch_list[i])) {
+			sap_debug("default channel chosen as %d",
+				  acs_cfg->ch_list[i]);
+			return acs_cfg->ch_list[i];
+		}
+	}
+
 	sap_debug("default channel chosen as %d", acs_cfg->ch_list[0]);
-	/* Return the default channel as first channel in list */
+
 	return acs_cfg->ch_list[0];
 }
 
@@ -3222,9 +3238,6 @@ static QDF_STATUS sap_get_freq_list(struct sap_context *sap_ctx,
 	uint8_t start_ch_num, band_start_ch;
 	uint8_t end_ch_num, band_end_ch;
 	uint32_t en_lte_coex;
-#ifdef FEATURE_WLAN_CH_AVOID
-	uint8_t i;
-#endif
 	struct mac_context *mac_ctx;
 	tSapChSelSpectInfo spect_info_obj = { NULL, 0 };
 	uint16_t ch_width;
@@ -3238,6 +3251,9 @@ static QDF_STATUS sap_get_freq_list(struct sap_context *sap_ctx,
 	}
 
 	dfs_master_enable = mac_ctx->mlme_cfg->dfs_cfg.dfs_master_capable;
+	if (sap_ctx->dfs_mode == ACS_DFS_MODE_DISABLE)
+		dfs_master_enable = false;
+
 	start_ch_num = sap_ctx->acs_cfg->start_ch;
 	end_ch_num = sap_ctx->acs_cfg->end_ch;
 	ch_width = sap_ctx->acs_cfg->ch_width;
@@ -3304,6 +3320,20 @@ static QDF_STATUS sap_get_freq_list(struct sap_context *sap_ctx,
 		     )))
 			continue;
 
+		/* check if the channel is in NOL blacklist */
+		if (sap_dfs_is_channel_in_nol_list(sap_ctx,
+		    WLAN_REG_CH_NUM(loop_count),
+		    PHY_SINGLE_CHANNEL_CENTERED)) {
+			sap_debug("Ch %d in NOL list",
+				  WLAN_REG_CH_NUM(loop_count));
+			continue;
+		}
+
+		/* Skip DSRC channels */
+		if (wlan_reg_is_dsrc_chan(mac_ctx->pdev,
+					  WLAN_REG_CH_NUM(loop_count)))
+			continue;
+
 		/*
 		 * Skip the channels which are not in ACS config from user
 		 * space
@@ -3332,33 +3362,7 @@ static QDF_STATUS sap_get_freq_list(struct sap_context *sap_ctx,
 		    wlan_reg_is_etsi13_srd_chan(mac_ctx->pdev,
 						WLAN_REG_CH_NUM(loop_count)))
 			continue;
-		/*
-		 * If we have any 5Ghz channel in the channel list
-		 * and bw is 40/80/160 Mhz then we don't want SAP to
-		 * come up in 2.4Ghz as for 40Mhz, 2.4Ghz channel is
-		 * not preferred and 80/160Mhz is not allowed for 2.4Ghz
-		 * band. So, don't even scan on 2.4Ghz channels if bw is
-		 * 40/80/160Mhz and channel list has any 5Ghz channel.
-		 */
-		if (end_ch_num >= WLAN_REG_CH_NUM(CHAN_ENUM_5180) &&
-		    ((ch_width == CH_WIDTH_40MHZ) ||
-		     (ch_width == CH_WIDTH_80MHZ) ||
-		     (ch_width == CH_WIDTH_80P80MHZ) ||
-		     (ch_width == CH_WIDTH_160MHZ))) {
-			if (WLAN_REG_CH_NUM(loop_count) >=
-			    WLAN_REG_CH_NUM(CHAN_ENUM_2412) &&
-			    WLAN_REG_CH_NUM(loop_count) <=
-			    WLAN_REG_CH_NUM(CHAN_ENUM_2484))
-				continue;
-		}
 
-#ifdef FEATURE_WLAN_CH_AVOID
-		for (i = 0; i < NUM_CHANNELS; i++) {
-			if (safe_channels[i].channelNumber ==
-			     WLAN_REG_CH_NUM(loop_count)) {
-				/* Check if channel is safe */
-				if (true == safe_channels[i].isSafe) {
-#endif
 #ifdef FEATURE_WLAN_AP_AP_ACS_OPTIMIZE
 		uint8_t ch;
 
@@ -3395,12 +3399,6 @@ static QDF_STATUS sap_get_freq_list(struct sap_context *sap_ctx,
 		list[ch_count] = wlan_reg_chan_to_freq(mac_ctx->pdev,
 						   WLAN_REG_CH_NUM(loop_count));
 		ch_count++;
-#endif
-#ifdef FEATURE_WLAN_CH_AVOID
-				}
-				break;
-			}
-		}
 #endif
 	}
 	if (0 == ch_count) {