wl12xx: fix forced passive scans

We were using incorrect max and min dwell times during forced passive
scans because we were still using the active scan states to scan
(passively) the channels that were not marked as passive.

Instead of doing passive scans in active states, we now skip active
states and scan for all channels in passive states.

Cc: <stable@kernel.org> # 2.6.36+
Signed-off-by: Luciano Coelho <coelho@ti.com>

drivers/net/wireless/wl12xx/scan.c

@@ -99,14 +99,18 @@ static int wl1271_get_scan_channels(struct wl1271 *wl,
 	for (i = 0, j = 0;
 	     i < req->n_channels && j < WL1271_SCAN_MAX_CHANNELS;
 	     i++) {
-
 		flags = req->channels[i]->flags;
 
 		if (!test_bit(i, wl->scan.scanned_ch) &&
 		    !(flags & IEEE80211_CHAN_DISABLED) &&
-		    ((!!(flags & IEEE80211_CHAN_PASSIVE_SCAN)) == passive) &&
-		    (req->channels[i]->band == band)) {
-
+		    (req->channels[i]->band == band) &&
+		    /*
+		     * In passive scans, we scan all remaining
+		     * channels, even if not marked as such.
+		     * In active scans, we only scan channels not
+		     * marked as passive.
+		     */
+		    (passive || !(flags & IEEE80211_CHAN_PASSIVE_SCAN))) {
 			wl1271_debug(DEBUG_SCAN, "band %d, center_freq %d ",
 				     req->channels[i]->band,
 				     req->channels[i]->center_freq);
@@ -158,6 +162,10 @@ static int wl1271_scan_send(struct wl1271 *wl, enum ieee80211_band band,
 	int ret;
 	u16 scan_options = 0;
 
+	/* skip active scans if we don't have SSIDs */
+	if (!passive && wl->scan.req->n_ssids == 0)
+		return WL1271_NOTHING_TO_SCAN;
+
 	cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
 	trigger = kzalloc(sizeof(*trigger), GFP_KERNEL);
 	if (!cmd || !trigger) {
@@ -165,8 +173,7 @@ static int wl1271_scan_send(struct wl1271 *wl, enum ieee80211_band band,
 		goto out;
 	}
 
-	/* No SSIDs means that we have a forced passive scan */
-	if (passive || wl->scan.req->n_ssids == 0)
+	if (passive)
 		scan_options |= WL1271_SCAN_OPT_PASSIVE;
 
 	if (WARN_ON(wl->role_id == WL12XX_INVALID_ROLE_ID)) {