qcacld-3.0: Filter SAP based upon ACS channel list

Scenario:
1. Start SAP on any potential LTE-COEX channel.
2. SAP would restart when it gets the event of unsafe channel.

Observation:
SAP restarts on a channel not in ACS channel list.

Expectation:
SAP should restart in channels given by the user
space only which are configured by hostapd.

Issue with driver:
Currently in wlansap_filter_ch_based_acs, the driver
eliminates the channels based upon the ACS start, and
end channel, and not the channel list, which can lead
to almost all the channels being picked, and none eliminated
if the start channel was 1, and end channel was 165, even
when only two channels, say 1 and 165 only were present
in ACS channel list.

Fix:
Fix is to eliminate all the candidate channels which were
not part of the ACS channel list, and pick only those channels
that were part of initial do_acs request.

Change-Id: Ib3b0b0a77c07b423b66e99feb085a370ed01f2de
CRs-Fixed: 2454270

core/sap/src/sap_module.c

@@ -2725,6 +2725,26 @@ QDF_STATUS wlansap_update_owe_info(struct sap_context *sap_ctx,
 	return status;
 }
 
+static bool wlansap_is_channel_present_in_acs_list(uint8_t ch,
+						uint8_t *ch_list,
+						uint8_t ch_count)
+{
+	uint8_t i;
+
+	for(i = 0; i < ch_count; i++) {
+		if (ch_list[i] == ch) {
+			/*
+			 * channel was given by hostpad for ACS, and is present
+			 * in PCL.
+			 */
+			sap_debug("channel present in ACS channel list %d", ch);
+			return true;
+		}
+	}
+
+	return false;
+}
+
 QDF_STATUS wlansap_filter_ch_based_acs(struct sap_context *sap_ctx,
 				       uint8_t *ch_list,
 				       uint32_t *ch_cnt)
@@ -2738,8 +2758,9 @@ QDF_STATUS wlansap_filter_ch_based_acs(struct sap_context *sap_ctx,
 	}
 
 	for (ch_index = 0; ch_index < *ch_cnt; ch_index++) {
-		if (ch_list[ch_index] >= sap_ctx->acs_cfg->start_ch &&
-		    ch_list[ch_index] <= sap_ctx->acs_cfg->end_ch)
+		if (wlansap_is_channel_present_in_acs_list(ch_list[ch_index],
+					     sap_ctx->acs_cfg->ch_list,
+					     sap_ctx->acs_cfg->ch_list_count))
 			ch_list[target_ch_cnt++] = ch_list[ch_index];
 	}