qcacld-3.0: Allow subsequent same ACS request even if ACS is in progress

To reduce the ACS time, there is an implementation wherein one
user space process creates sap interface and queues ACS request to driver,
meantime framework initializes various config and starts hostapd
to queue same ACS request to driver. In this scenario, there is a
race condition that hostapd tries to queue ACS request while there is
already one ACS request is in progress. With current implementation,
driver will reject second ACS request and return error to hostapd
leading to sap turn on failure.

This change allows subsequent ACS request if all the attributes
of do_acs vendor command matches with the ongoing ACS request and returns
success to userspace. There is no another ACS scan queued as part of
second ACS request which is same as ongoing ACS request because the result
of ongoing ACS request will act as result of second ACS request as well.

Change-Id: I67d10b09be922745e7ffb46192e00135dbdb9de4
CRs-Fixed: 3295786

core/hdd/src/wlan_hdd_cfg80211.c

@@ -3291,6 +3291,116 @@ static uint16_t wlan_hdd_update_bw_from_mlme(struct hdd_context *hdd_ctx,
 	return temp_ch_width;
 }
 
+/**
+ *  wlan_hdd_check_is_acs_request_same() - API to compare ongoing ACS and
+ *					current received ACS request
+ * @adapter: hdd adapter
+ * @data: ACS data
+ * @data_len: ACS data length
+ *
+ * This function is used to compare ongoing ACS params with current received
+ * ACS request on same interface.
+ *
+ * Return: true only if ACS request received is same as ongoing ACS
+ */
+static bool wlan_hdd_check_is_acs_request_same(struct hdd_adapter *adapter,
+					       const void *data, int data_len)
+{
+	struct nlattr *tb[QCA_WLAN_VENDOR_ATTR_ACS_MAX + 1];
+	uint8_t hw_mode, ht_enabled, ht40_enabled, vht_enabled, eht_enabled;
+	struct sap_config *sap_config;
+	uint32_t last_scan_ageout_time;
+	uint8_t ch_list_count;
+	uint16_t ch_width;
+	int ret, i, j;
+
+	ret = wlan_cfg80211_nla_parse(tb, QCA_WLAN_VENDOR_ATTR_ACS_MAX, data,
+				      data_len,
+				      wlan_hdd_cfg80211_do_acs_policy);
+	if (ret) {
+		hdd_err("Invalid ATTR");
+		return false;
+	}
+
+	if (!tb[QCA_WLAN_VENDOR_ATTR_ACS_HW_MODE])
+		return false;
+
+	sap_config = &adapter->session.ap.sap_config;
+
+	hw_mode = nla_get_u8(tb[QCA_WLAN_VENDOR_ATTR_ACS_HW_MODE]);
+	if (sap_config->acs_cfg.master_acs_cfg.hw_mode != hw_mode)
+		return false;
+
+	ht_enabled = nla_get_flag(tb[QCA_WLAN_VENDOR_ATTR_ACS_HT_ENABLED]);
+	if (sap_config->acs_cfg.master_acs_cfg.ht != ht_enabled)
+		return false;
+
+	ht40_enabled = nla_get_flag(tb[QCA_WLAN_VENDOR_ATTR_ACS_HT40_ENABLED]);
+	if (sap_config->acs_cfg.master_acs_cfg.ht40 != ht40_enabled)
+		return false;
+
+	vht_enabled = nla_get_flag(tb[QCA_WLAN_VENDOR_ATTR_ACS_VHT_ENABLED]);
+	if (sap_config->acs_cfg.master_acs_cfg.vht != vht_enabled)
+		return false;
+
+	eht_enabled = nla_get_flag(tb[QCA_WLAN_VENDOR_ATTR_ACS_EHT_ENABLED]);
+	if (sap_config->acs_cfg.master_acs_cfg.eht != eht_enabled)
+		return false;
+
+	if (tb[QCA_WLAN_VENDOR_ATTR_ACS_CHWIDTH])
+		ch_width = nla_get_u16(tb[QCA_WLAN_VENDOR_ATTR_ACS_CHWIDTH]);
+	else
+		ch_width = 0;
+	if (sap_config->acs_cfg.master_acs_cfg.ch_width != ch_width)
+		return false;
+
+	if (nla_get_u32(tb[QCA_WLAN_VENDOR_ATTR_ACS_LAST_SCAN_AGEOUT_TIME]))
+		last_scan_ageout_time =
+		nla_get_u32(tb[QCA_WLAN_VENDOR_ATTR_ACS_LAST_SCAN_AGEOUT_TIME]);
+	else
+		last_scan_ageout_time = 0;
+	if (sap_config->acs_cfg.last_scan_ageout_time != last_scan_ageout_time)
+		return false;
+
+	if (tb[QCA_WLAN_VENDOR_ATTR_ACS_FREQ_LIST]) {
+		uint32_t *freq =
+			nla_data(tb[QCA_WLAN_VENDOR_ATTR_ACS_FREQ_LIST]);
+
+		ch_list_count = nla_len(
+				tb[QCA_WLAN_VENDOR_ATTR_ACS_FREQ_LIST]) /
+				sizeof(uint32_t);
+		if (sap_config->acs_cfg.master_ch_list_count != ch_list_count)
+			return false;
+		for (i = 0; i < ch_list_count; i++) {
+			j = 0;
+			while (j < ch_list_count && freq[i] !=
+			       sap_config->acs_cfg.master_freq_list[j])
+				j++;
+			if (j == ch_list_count)
+				return false;
+		}
+	} else if (tb[QCA_WLAN_VENDOR_ATTR_ACS_CH_LIST]) {
+		uint8_t *tmp = nla_data(tb[QCA_WLAN_VENDOR_ATTR_ACS_CH_LIST]);
+
+		ch_list_count = nla_len(
+					tb[QCA_WLAN_VENDOR_ATTR_ACS_CH_LIST]);
+		if (sap_config->acs_cfg.master_ch_list_count != ch_list_count)
+			return false;
+		for (i = 0; i < ch_list_count; i++) {
+			j = 0;
+			while (j < ch_list_count &&
+			       wlan_reg_legacy_chan_to_freq(
+			       adapter->hdd_ctx->pdev, tmp[i]) !=
+			       sap_config->acs_cfg.master_freq_list[j])
+				j++;
+			if (j == ch_list_count)
+				return false;
+		}
+	}
+
+	return true;
+}
+
 /**
  * __wlan_hdd_cfg80211_do_acs(): CFG80211 handler function for DO_ACS Vendor CMD
  * @wiphy:  Linux wiphy struct pointer
@@ -3366,7 +3476,13 @@ static int __wlan_hdd_cfg80211_do_acs(struct wiphy *wiphy,
 	}
 
 	if (qdf_atomic_read(&adapter->session.ap.acs_in_progress) > 0) {
-		hdd_err("ACS rejected as previous req already in progress");
+		if (wlan_hdd_check_is_acs_request_same(adapter,
+						       data, data_len)) {
+			hdd_debug("Same ACS req as ongoing is received, return success");
+			ret = 0;
+			goto out;
+		}
+		hdd_err("ACS rejected as previous ACS req already in progress");
 		return -EINVAL;
 	} else {
 		qdf_atomic_set(&adapter->session.ap.acs_in_progress, 1);
@@ -3388,8 +3504,15 @@ static int __wlan_hdd_cfg80211_do_acs(struct wiphy *wiphy,
 		ret = -EINVAL;
 		goto out;
 	}
-	hw_mode = nla_get_u8(tb[QCA_WLAN_VENDOR_ATTR_ACS_HW_MODE]);
 
+	sap_config = &adapter->session.ap.sap_config;
+
+	/* Check and free if memory is already allocated for acs channel list */
+	wlan_hdd_undo_acs(adapter);
+
+	qdf_mem_zero(&sap_config->acs_cfg, sizeof(struct sap_acs_cfg));
+
+	hw_mode = nla_get_u8(tb[QCA_WLAN_VENDOR_ATTR_ACS_HW_MODE]);
 	hdd_nofl_info("ACS request vid %d hw mode %d", adapter->vdev_id,
 		      hw_mode);
 	ht_enabled = nla_get_flag(tb[QCA_WLAN_VENDOR_ATTR_ACS_HT_ENABLED]);
@@ -3397,6 +3520,12 @@ static int __wlan_hdd_cfg80211_do_acs(struct wiphy *wiphy,
 	vht_enabled = nla_get_flag(tb[QCA_WLAN_VENDOR_ATTR_ACS_VHT_ENABLED]);
 	eht_enabled = nla_get_flag(tb[QCA_WLAN_VENDOR_ATTR_ACS_EHT_ENABLED]);
 
+	sap_config->acs_cfg.master_acs_cfg.hw_mode = hw_mode;
+	sap_config->acs_cfg.master_acs_cfg.ht = ht_enabled;
+	sap_config->acs_cfg.master_acs_cfg.ht40 = ht40_enabled;
+	sap_config->acs_cfg.master_acs_cfg.vht = vht_enabled;
+	sap_config->acs_cfg.master_acs_cfg.eht = eht_enabled;
+
 	if (((adapter->device_mode == QDF_SAP_MODE) &&
 	      sap_force_11n_for_11ac) ||
 	    ((adapter->device_mode == QDF_P2P_GO_MODE) &&
@@ -3407,11 +3536,13 @@ static int __wlan_hdd_cfg80211_do_acs(struct wiphy *wiphy,
 
 	if (tb[QCA_WLAN_VENDOR_ATTR_ACS_CHWIDTH]) {
 		ch_width = nla_get_u16(tb[QCA_WLAN_VENDOR_ATTR_ACS_CHWIDTH]);
+		sap_config->acs_cfg.master_acs_cfg.ch_width = ch_width;
 	} else {
 		if (ht_enabled && ht40_enabled)
 			ch_width = 40;
 		else
 			ch_width = 20;
+		sap_config->acs_cfg.master_acs_cfg.ch_width = 0;
 	}
 
 	if (tb[QCA_WLAN_VENDOR_ATTR_ACS_EHT_ENABLED])
@@ -3439,13 +3570,6 @@ static int __wlan_hdd_cfg80211_do_acs(struct wiphy *wiphy,
 	else
 		last_scan_ageout_time = 0;
 
-	sap_config = &adapter->session.ap.sap_config;
-
-	/* Check and free if memory is already allocated for acs channel list */
-	wlan_hdd_undo_acs(adapter);
-
-	qdf_mem_zero(&sap_config->acs_cfg, sizeof(struct sap_acs_cfg));
-
 	if (ch_width == 320)
 		wlan_hdd_set_sap_acs_ch_width_320(sap_config);
 	else if (ch_width == 160)

core/sap/inc/sap_api.h

@@ -425,6 +425,24 @@ typedef struct sap_SSIDInfo {
 	uint8_t ssidHidden;
 } qdf_packed tSap_SSIDInfo_t;
 
+/**
+ * struct master_acs - acs attributes received from userspace
+ * @hw_mode: hw mode
+ * @ht: ht flag
+ * @ht40: ht40 flag
+ * @vht: vht flag
+ * @eht: eht flag
+ * @ch_width: channel bandwidth
+ */
+struct master_acs {
+	uint8_t    hw_mode;
+	uint8_t    ht;
+	uint8_t    ht40;
+	uint8_t    vht;
+	uint8_t    eht;
+	uint16_t   ch_width;
+};
+
 struct sap_acs_cfg {
 	/* ACS Algo Input */
 	uint8_t    acs_mode;
@@ -461,6 +479,7 @@ struct sap_acs_cfg {
 #endif
 	bool       skip_acs_scan;
 	uint32_t   last_scan_ageout_time;
+	struct master_acs master_acs_cfg;
 };
 
 /*