qcacld-3.0: Fix acs select channel with unexpected bw

When AGO starts ACS with 160Mhz, and driver selects 5660Mhz based on
channel weight because no 160mhz channel available at the time.
But ch freq 5660Mhz is not in PCL for AGO, driver selects 5825Mhz
based on channel weight. 5825Mhz only supports 20Mhz in current
regdomain and it's not preferred channel bw.
Fix by try fallback to lower bandwidth channel if request bw channel
unavailable.

Change-Id: I5646aefc5fbd48acb1396edf0e182616391e027c
CRs-Fixed: 3018731

core/sap/src/sap_ch_select.c

@@ -2457,6 +2457,18 @@ static bool sap_is_ch_non_overlap(struct sap_context *sap_ctx, uint16_t ch)
 	return false;
 }
 
+static enum phy_ch_width
+sap_acs_next_lower_bandwidth(enum phy_ch_width ch_width)
+{
+	if (ch_width <= CH_WIDTH_20MHZ ||
+	    ch_width == CH_WIDTH_5MHZ ||
+	    ch_width == CH_WIDTH_10MHZ ||
+	    ch_width >= CH_WIDTH_INVALID)
+		return CH_WIDTH_INVALID;
+
+	return wlan_reg_get_next_lower_bandwidth(ch_width);
+}
+
 uint32_t sap_select_channel(mac_handle_t mac_handle,
 			   struct sap_context *sap_ctx,
 			   qdf_list_t *scan_list)
@@ -2547,7 +2559,13 @@ uint32_t sap_select_channel(mac_handle_t mac_handle,
 	 */
 	if (!ch_in_pcl(sap_ctx, best_chan_freq)) {
 		uint32_t cal_chan_freq, cal_chan_weight;
+
+		enum phy_ch_width pref_bw = sap_ctx->acs_cfg->ch_width;
+next_bw:
+		sap_debug("check bw %d", pref_bw);
 		for (count = 0; count < spect_info->numSpectChans; count++) {
+			struct ch_params ch_params = {0};
+
 			cal_chan_freq = spect_info->pSpectCh[count].chan_freq;
 			cal_chan_weight = spect_info->pSpectCh[count].weight;
 			/* skip pcl channel whose weight is bigger than best */
@@ -2563,13 +2581,21 @@ uint32_t sap_select_channel(mac_handle_t mac_handle,
 				spect_info)
 				== SAP_CHANNEL_NOT_SELECTED)
 				continue;
-
+			ch_params.ch_width = pref_bw;
+			wlan_reg_set_channel_params_for_freq(
+				mac_ctx->pdev, cal_chan_freq, 0, &ch_params);
+			if (ch_params.ch_width != pref_bw)
+				continue;
 			best_chan_freq = cal_chan_freq;
-			sap_debug("Changed best freq to %d Preferred freq",
-				  best_chan_freq);
-
+			sap_debug("Changed best freq to %d Preferred freq bw %d",
+				  best_chan_freq, pref_bw);
 			break;
 		}
+		if (count == spect_info->numSpectChans) {
+			pref_bw = sap_acs_next_lower_bandwidth(pref_bw);
+			if (pref_bw != CH_WIDTH_INVALID)
+				goto next_bw;
+		}
 	}
 
 	sap_ctx->acs_cfg->pri_ch_freq = best_chan_freq;