brcmfmac: allow scanning to be suppressed in the driver

During the DHCP protocol exchange it is benificial to suppress
scan requests which may decrease time to complete DHCP protocol.

Reviewed-by: Hante Meuleman <meuleman@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/brcm80211/brcmfmac/wl_cfg80211.c

@@ -856,6 +856,11 @@ brcmf_cfg80211_escan(struct wiphy *wiphy, struct brcmf_cfg80211_vif *vif,
 			  cfg->scan_status);
 		return -EAGAIN;
 	}
+	if (test_bit(BRCMF_SCAN_STATUS_SUPPRESS, &cfg->scan_status)) {
+		brcmf_err("Scanning suppressed: status (%lu)\n",
+			  cfg->scan_status);
+		return -EAGAIN;
+	}
 	if (test_bit(BRCMF_VIF_STATUS_CONNECTING, &ifp->vif->sme_state)) {
 		brcmf_err("Connecting: status (%lu)\n", ifp->vif->sme_state);
 		return -EAGAIN;
@@ -3017,6 +3022,11 @@ brcmf_cfg80211_sched_scan_start(struct wiphy *wiphy,
 		brcmf_err("Scanning already: status (%lu)\n", cfg->scan_status);
 		return -EAGAIN;
 	}
+	if (test_bit(BRCMF_SCAN_STATUS_SUPPRESS, &cfg->scan_status)) {
+		brcmf_err("Scanning suppressed: status (%lu)\n",
+			  cfg->scan_status);
+		return -EAGAIN;
+	}
 
 	if (!request->n_ssids || !request->n_match_sets) {
 		brcmf_err("Invalid sched scan req!! n_ssids:%d\n",

drivers/net/wireless/brcm80211/brcmfmac/wl_cfg80211.h

@@ -77,14 +77,16 @@
 
 
 /**
- * enum brcmf_scan_status - dongle scan status
+ * enum brcmf_scan_status - scan engine status
  *
  * @BRCMF_SCAN_STATUS_BUSY: scanning in progress on dongle.
  * @BRCMF_SCAN_STATUS_ABORT: scan being aborted on dongle.
+ * @BRCMF_SCAN_STATUS_SUPPRESS: scanning is suppressed in driver.
  */
 enum brcmf_scan_status {
 	BRCMF_SCAN_STATUS_BUSY,
 	BRCMF_SCAN_STATUS_ABORT,
+	BRCMF_SCAN_STATUS_SUPPRESS,
 };
 
 /**