qcacld-3.0: Fix SAP restart failure

qcacld-2.0 to qcacld-3.0 propagation

When the driver is configured to "force SCC" mode by
gWlanMccToSccSwitchMode = 2, in STA+SAP case, the
driver will check the SAP channel to avoid the
MCC in same band(2.4G or 5G) and override if necessary.
During ACS process, the SAP sapContext->channel is 0.
The driver doesn't validate it before uses it in
sapGotoChannelSel when applies the "force SCC" logic.
That causes an invalid channel selection for the SAP.
And finally causes the hostapd starting failed.
This fix is to skip the override logic if the
sapContext->channel is 0. When the SAP is starting with
a valid channel, the override logic will be activated
again.

Change-Id: I8e3d171ac47d8be149df98ae3e30c8df391a15b0
CRs-Fixed: 1033277

core/sap/src/sap_fsm.c

@@ -2215,7 +2215,18 @@ QDF_STATUS sap_goto_channel_sel(ptSapContext sap_context,
 #endif
 #ifdef FEATURE_WLAN_MCC_TO_SCC_SWITCH
 		if (sap_context->cc_switch_mode !=
-						QDF_MCC_TO_SCC_SWITCH_DISABLE) {
+					QDF_MCC_TO_SCC_SWITCH_DISABLE &&
+					sap_context->channel) {
+			/*
+			 * For ACS request ,the sapContext->channel is 0,
+			 * we skip below overlap checking. When the ACS
+			 * finish and SAPBSS start, the sapContext->channel
+			 * will not be 0. Then the overlap checking will be
+			 * reactivated.If we use sapContext->channel = 0
+			 * to perform the overlap checking, an invalid overlap
+			 * channel con_ch could becreated. That may cause
+			 * SAP start failed.
+			 */
 			con_ch = sme_check_concurrent_channel_overlap(h_hal,
 					sap_context->channel,
 					sap_context->csr_roamProfile.phyMode,
@@ -2245,7 +2256,8 @@ QDF_STATUS sap_goto_channel_sel(ptSapContext sap_context,
 #endif
 #ifdef FEATURE_WLAN_MCC_TO_SCC_SWITCH
 		if (sap_context->cc_switch_mode !=
-						QDF_MCC_TO_SCC_SWITCH_DISABLE) {
+					QDF_MCC_TO_SCC_SWITCH_DISABLE &&
+					sap_context->channel) {
 			QDF_TRACE(QDF_MODULE_ID_SAP, QDF_TRACE_LEVEL_INFO,
 				FL("check for overlap: chan:%d mode:%d"),
 				sap_context->channel,