mwifiex: send regulatory domain info to firmware only if alpha2 changed

On cfg80211 regulatory domain change, drivers gets alpha2 country
code or "00" in driver's notification handler.

In most cases, the pattern will be US, 00, US, 00, US, 00, US, ...
There is no need to send domain info to firmware in case of "00" or
with the same alpha2 country code.
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/mwifiex/cfg80211.c

@@ -542,19 +542,26 @@ static void mwifiex_reg_notifier(struct wiphy *wiphy,
 	wiphy_dbg(wiphy, "info: cfg80211 regulatory domain callback for %c%c\n",
 		  request->alpha2[0], request->alpha2[1]);
 
-	memcpy(adapter->country_code, request->alpha2, sizeof(request->alpha2));
-
 	switch (request->initiator) {
 	case NL80211_REGDOM_SET_BY_DRIVER:
 	case NL80211_REGDOM_SET_BY_CORE:
 	case NL80211_REGDOM_SET_BY_USER:
-		break;
-		/* Todo: apply driver specific changes in channel flags based
-		   on the request initiator if necessary. */
 	case NL80211_REGDOM_SET_BY_COUNTRY_IE:
 		break;
+	default:
+		wiphy_err(wiphy, "unknown regdom initiator: %d\n",
+			  request->initiator);
+		return;
 	}
+
+	/* Don't send world or same regdom info to firmware */
+	if (strncmp(request->alpha2, "00", 2) &&
+	    strncmp(request->alpha2, adapter->country_code,
+		    sizeof(request->alpha2))) {
+		memcpy(adapter->country_code, request->alpha2,
+		       sizeof(request->alpha2));
 		mwifiex_send_domain_info_cmd_fw(wiphy);
+	}
 }
 
 /*

drivers/net/wireless/mwifiex/sta_ioctl.c

@@ -205,6 +205,14 @@ static int mwifiex_process_country_ie(struct mwifiex_private *priv,
 		return 0;
 	}
 
+	if (!strncmp(priv->adapter->country_code, &country_ie[2], 2)) {
+		rcu_read_unlock();
+		wiphy_dbg(priv->wdev->wiphy,
+			  "11D: skip setting domain info in FW\n");
+		return 0;
+	}
+	memcpy(priv->adapter->country_code, &country_ie[2], 2);
+
 	domain_info->country_code[0] = country_ie[2];
 	domain_info->country_code[1] = country_ie[3];
 	domain_info->country_code[2] = ' ';