qcacld-3.0: Refine ACS fail-safe channel selection

1) Change some of the parameters for the following two functions
to reflect the right PHY mode definitions at different layers:

wlan_hdd_set_acs_ch_range
sap_select_default_oper_chan

2) Refine the kernel-doc for the above 2 functions due to their
parameter changes.

3) Use eCsrPhyMode instead of uint32_t to define hw_mode in
struct sap_acs_cfg to reflect the right PHY mode definition.

4) Refine the ACS code logic due to the changes introduced above.

Change-Id: I91b7814831a05265cfff456452eef0fe2ef97d1e
CRs-Fixed: 2167355

core/hdd/src/wlan_hdd_cfg80211.c

@@ -1722,32 +1722,37 @@ static int wlan_hdd_reset_force_acs_chan_range(struct hdd_context *hdd_ctx,
 }
 
 /**
- * wlan_hdd_set_acs_ch_range : Start ACS channel range values
+ * wlan_hdd_set_acs_ch_range : Populate ACS hw mode and channel range values
  * @sap_cfg: pointer to SAP config struct
+ * @hw_mode: hw mode retrieved from vendor command buffer
+ * @ht_enabled: whether HT phy mode is enabled
+ * @vht_enabled: whether VHT phy mode is enabled
  *
- * This function sets the default ACS start and end channel for the given band
- * and also parses the given ACS channel list.
+ * This function populates the ACS hw mode based on the configuration retrieved
+ * from the vendor command buffer; and sets ACS start and end channel for the
+ * given band.
  *
- * Return: status
+ * Return: 0 if success; -EINVAL if ACS channel list is NULL
  */
-static int wlan_hdd_set_acs_ch_range(tsap_Config_t *sap_cfg, bool ht_enabled,
-							bool vht_enabled)
+static int wlan_hdd_set_acs_ch_range(
+	tsap_Config_t *sap_cfg, enum qca_wlan_vendor_acs_hw_mode hw_mode,
+	bool ht_enabled, bool vht_enabled)
 {
 	int i;
 
-	if (sap_cfg->acs_cfg.hw_mode == QCA_ACS_MODE_IEEE80211B) {
+	if (hw_mode == QCA_ACS_MODE_IEEE80211B) {
 		sap_cfg->acs_cfg.hw_mode = eCSR_DOT11_MODE_11b;
 		sap_cfg->acs_cfg.start_ch = WLAN_REG_CH_NUM(CHAN_ENUM_1);
 		sap_cfg->acs_cfg.end_ch = WLAN_REG_CH_NUM(CHAN_ENUM_14);
-	} else if (sap_cfg->acs_cfg.hw_mode == QCA_ACS_MODE_IEEE80211G) {
+	} else if (hw_mode == QCA_ACS_MODE_IEEE80211G) {
 		sap_cfg->acs_cfg.hw_mode = eCSR_DOT11_MODE_11g;
 		sap_cfg->acs_cfg.start_ch = WLAN_REG_CH_NUM(CHAN_ENUM_1);
 		sap_cfg->acs_cfg.end_ch = WLAN_REG_CH_NUM(CHAN_ENUM_13);
-	} else if (sap_cfg->acs_cfg.hw_mode == QCA_ACS_MODE_IEEE80211A) {
+	} else if (hw_mode == QCA_ACS_MODE_IEEE80211A) {
 		sap_cfg->acs_cfg.hw_mode = eCSR_DOT11_MODE_11a;
 		sap_cfg->acs_cfg.start_ch = WLAN_REG_CH_NUM(CHAN_ENUM_36);
 		sap_cfg->acs_cfg.end_ch = WLAN_REG_CH_NUM(CHAN_ENUM_165);
-	} else if (sap_cfg->acs_cfg.hw_mode == QCA_ACS_MODE_IEEE80211ANY) {
+	} else if (hw_mode == QCA_ACS_MODE_IEEE80211ANY) {
 		sap_cfg->acs_cfg.hw_mode = eCSR_DOT11_MODE_abg;
 		sap_cfg->acs_cfg.start_ch = WLAN_REG_CH_NUM(CHAN_ENUM_1);
 		sap_cfg->acs_cfg.end_ch = WLAN_REG_CH_NUM(CHAN_ENUM_165);
@@ -2505,7 +2510,8 @@ static int __wlan_hdd_cfg80211_do_acs(struct wiphy *wiphy,
 	int status = -EINVAL, i = 0;
 	struct nlattr *tb[QCA_WLAN_VENDOR_ATTR_ACS_MAX + 1];
 	bool ht_enabled, ht40_enabled, vht_enabled;
-	uint8_t ch_width, hw_mode;
+	uint8_t ch_width;
+	enum qca_wlan_vendor_acs_hw_mode hw_mode;
 	QDF_STATUS qdf_status;
 
 	/* ***Note*** Donot set SME config related to ACS operation here because
@@ -2557,8 +2563,6 @@ static int __wlan_hdd_cfg80211_do_acs(struct wiphy *wiphy,
 		goto out;
 	}
 	hw_mode = nla_get_u8(tb[QCA_WLAN_VENDOR_ATTR_ACS_HW_MODE]);
-	/* This value will be overwritten in wlan_hdd_set_acs_ch_range */
-	sap_config->acs_cfg.hw_mode = hw_mode;
 
 	if (tb[QCA_WLAN_VENDOR_ATTR_ACS_HT_ENABLED])
 		ht_enabled =
@@ -2685,7 +2689,8 @@ static int __wlan_hdd_cfg80211_do_acs(struct wiphy *wiphy,
 				  pcl_channels_weight_list[i]);
 	}
 
-	status = wlan_hdd_set_acs_ch_range(sap_config, ht_enabled, vht_enabled);
+	status = wlan_hdd_set_acs_ch_range(sap_config, hw_mode,
+					   ht_enabled, vht_enabled);
 	if (status) {
 		hdd_err("set acs channel range failed");
 		goto out;

core/sap/inc/sap_api.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012-2017 The Linux Foundation. All rights reserved.
+ * Copyright (c) 2012-2018 The Linux Foundation. All rights reserved.
  *
  * Previously licensed under the ISC license by Qualcomm Atheros, Inc.
  *
@@ -495,7 +495,7 @@ typedef struct sap_SSIDInfo {
 struct sap_acs_cfg {
 	/* ACS Algo Input */
 	uint8_t    acs_mode;
-	uint32_t    hw_mode;
+	eCsrPhyMode hw_mode;
 	uint8_t    start_ch;
 	uint8_t    end_ch;
 	uint8_t    *ch_list;

core/sap/src/sap_api_link_cntl.c

@@ -311,8 +311,7 @@ QDF_STATUS wlansap_pre_start_bss_acs_scan_callback(tHalHandle hal_handle,
 			FL("CSR scan_status = eCSR_SCAN_ABORT/FAILURE (%d), choose default channel"),
 			scan_status);
 		sap_ctx->channel =
-			sap_select_default_oper_chan(hal_handle,
-					sap_ctx->acs_cfg);
+			sap_select_default_oper_chan(sap_ctx->acs_cfg);
 		sap_ctx->sap_state = eSAP_ACS_CHANNEL_SELECTED;
 		sap_ctx->sap_status = eSAP_STATUS_SUCCESS;
 		goto close_session;
@@ -377,8 +376,7 @@ QDF_STATUS wlansap_pre_start_bss_acs_scan_callback(tHalHandle hal_handle,
 	} else {
 #else
 		sap_ctx->channel =
-			sap_select_default_oper_chan(hal_handle,
-				sap_ctx->acs_cfg);
+			sap_select_default_oper_chan(sap_ctx->acs_cfg);
 	} else {
 #endif
 		/* Valid Channel Found from scan results. */

core/sap/src/sap_fsm.c

@@ -1622,15 +1622,7 @@ sap_dfs_is_channel_in_nol_list(struct sap_context *sap_context,
 	return false;
 }
 
-/**
- * sap_select_default_oper_chan() - Select operating channel based on acs hwmode
- * @hal: pointer to HAL
- * @acs_cfg: ACS config info
- *
- * Return: selected operating channel
- */
-uint8_t sap_select_default_oper_chan(tHalHandle hal,
-		struct sap_acs_cfg *acs_cfg)
+uint8_t sap_select_default_oper_chan(struct sap_acs_cfg *acs_cfg)
 {
 	uint8_t channel;
 
@@ -1641,21 +1633,21 @@ uint8_t sap_select_default_oper_chan(tHalHandle hal,
 		return 0;
 	}
 
-	if (acs_cfg->hw_mode == eCSR_DOT11_MODE_11a)
+	if (acs_cfg->hw_mode == eCSR_DOT11_MODE_11a) {
 		channel = SAP_DEFAULT_5GHZ_CHANNEL;
-	else if ((acs_cfg->hw_mode == eCSR_DOT11_MODE_11n) ||
-		(acs_cfg->hw_mode == eCSR_DOT11_MODE_11n_ONLY) ||
-		(acs_cfg->hw_mode == eCSR_DOT11_MODE_11ac) ||
-		(acs_cfg->hw_mode == eCSR_DOT11_MODE_11ac_ONLY) ||
-		(acs_cfg->hw_mode == eCSR_DOT11_MODE_11ax) ||
-		(acs_cfg->hw_mode == eCSR_DOT11_MODE_11ax_ONLY)) {
+	} else if ((acs_cfg->hw_mode == eCSR_DOT11_MODE_11n) ||
+		   (acs_cfg->hw_mode == eCSR_DOT11_MODE_11n_ONLY) ||
+		   (acs_cfg->hw_mode == eCSR_DOT11_MODE_11ac) ||
+		   (acs_cfg->hw_mode == eCSR_DOT11_MODE_11ac_ONLY) ||
+		   (acs_cfg->hw_mode == eCSR_DOT11_MODE_11ax) ||
+		   (acs_cfg->hw_mode == eCSR_DOT11_MODE_11ax_ONLY)) {
 		if (WLAN_REG_IS_5GHZ_CH(acs_cfg->start_ch))
 			channel = SAP_DEFAULT_5GHZ_CHANNEL;
 		else
 			channel = SAP_DEFAULT_24GHZ_CHANNEL;
-	}
-	else
+	} else {
 		channel = SAP_DEFAULT_24GHZ_CHANNEL;
+	}
 
 	QDF_TRACE(QDF_MODULE_ID_SAP, QDF_TRACE_LEVEL_INFO,
 			FL("channel selected to start bss %d"), channel);
@@ -1886,8 +1878,7 @@ QDF_STATUS sap_goto_channel_sel(struct sap_context *sap_context,
 			QDF_TRACE(QDF_MODULE_ID_SAP, QDF_TRACE_LEVEL_INFO_HIGH,
 				  FL("SAP Configuring default channel, Ch=%d"),
 				  sap_context->channel);
-			sap_context->channel =
-				sap_select_default_oper_chan(h_hal,
+			sap_context->channel = sap_select_default_oper_chan(
 					sap_context->acs_cfg);
 
 #ifdef SOFTAP_CHANNEL_RANGE

core/sap/src/sap_internal.h

@@ -472,9 +472,19 @@ void sap_scan_event_callback(struct wlan_objmgr_vdev *vdev,
  */
 uint8_t sap_indicate_radar(struct sap_context *sap_ctx);
 
+/**
+ * sap_select_default_oper_chan() - Select AP mode default operating channel
+ * @acs_cfg: pointer to ACS config info
+ *
+ * Select AP mode default operating channel based on ACS hw mode and channel
+ * range configuration when ACS scan fails due to some reasons, such as scan
+ * timeout, etc.
+ *
+ * Return: Selected operating channel number
+ */
+uint8_t sap_select_default_oper_chan(struct sap_acs_cfg *acs_cfg);
+
 #ifdef __cplusplus
 }
 #endif
-uint8_t sap_select_default_oper_chan(tHalHandle hal,
-		struct sap_acs_cfg *acs_cfg);
 #endif