wl12xx: use a bitmask instead of list of booleans in scanned_ch

We were using an array of booleans to mark the channels we had already
scanned.  This was causing a sparse error, because bool is not a type
with defined size.  To fix this, use bitmasks instead, which is much
cleaner anyway.

Thanks Johannes Berg for the idea.

Signed-off-by: Luciano Coelho <coelho@ti.com>

3 files changed, 17 insertions, 10 deletions

diff --git a/drivers/net/wireless/wl12xx/main.c b/drivers/net/wireless/wl12xx/main.c
index 85cb4daac9a0..9663326c0dfa 100644
--- a/drivers/net/wireless/wl12xx/main.c
+++ b/drivers/net/wireless/wl12xx/main.c
@@ -1423,8 +1423,7 @@ static void __wl1271_op_remove_interface(struct wl1271 *wl)
 
         if (wl->scan.state != WL1271_SCAN_STATE_IDLE) {
                 wl->scan.state = WL1271_SCAN_STATE_IDLE;
-                kfree(wl->scan.scanned_ch);
-                wl->scan.scanned_ch = NULL;
+                memset(wl->scan.scanned_ch, 0, sizeof(wl->scan.scanned_ch));
                 wl->scan.req = NULL;
                 ieee80211_scan_completed(wl->hw, true);
         }
@@ -3502,6 +3501,10 @@ int wl1271_init_ieee80211(struct wl1271 *wl)
         wl->hw->wiphy->max_scan_ie_len = WL1271_CMD_TEMPL_MAX_SIZE -
                         sizeof(struct ieee80211_header);
 
+        /* make sure all our channels fit in the scanned_ch bitmask */
+        BUILD_BUG_ON(ARRAY_SIZE(wl1271_channels) +
+                     ARRAY_SIZE(wl1271_channels_5ghz) >
+                     WL1271_MAX_CHANNELS);
         /*
          * We keep local copies of the band structs because we need to
          * modify them on a per-device basis.
diff --git a/drivers/net/wireless/wl12xx/scan.c b/drivers/net/wireless/wl12xx/scan.c
index 420653a2859c..5d0544c8f3f5 100644
--- a/drivers/net/wireless/wl12xx/scan.c
+++ b/drivers/net/wireless/wl12xx/scan.c
@@ -48,8 +48,7 @@ void wl1271_scan_complete_work(struct work_struct *work)
                 goto out;
 
         wl->scan.state = WL1271_SCAN_STATE_IDLE;
-        kfree(wl->scan.scanned_ch);
-        wl->scan.scanned_ch = NULL;
+        memset(wl->scan.scanned_ch, 0, sizeof(wl->scan.scanned_ch));
         wl->scan.req = NULL;
         ieee80211_scan_completed(wl->hw, false);
 
@@ -87,7 +86,7 @@ static int wl1271_get_scan_channels(struct wl1271 *wl,
 
                 flags = req->channels[i]->flags;
 
-                if (!wl->scan.scanned_ch[i] &&
+                if (!test_bit(i, wl->scan.scanned_ch) &&
                     !(flags & IEEE80211_CHAN_DISABLED) &&
                     ((!!(flags & IEEE80211_CHAN_PASSIVE_SCAN)) == passive) &&
                     (req->channels[i]->band == band)) {
@@ -124,7 +123,7 @@ static int wl1271_get_scan_channels(struct wl1271 *wl,
                         memset(&channels[j].bssid_msb, 0xff, 2);
 
                         /* Mark the channels we already used */
-                        wl->scan.scanned_ch[i] = true;
+                        set_bit(i, wl->scan.scanned_ch);
 
                         j++;
                 }
@@ -291,6 +290,12 @@ void wl1271_scan_stm(struct wl1271 *wl)
 int wl1271_scan(struct wl1271 *wl, const u8 *ssid, size_t ssid_len,
                 struct cfg80211_scan_request *req)
 {
+        /*
+         * cfg80211 should guarantee that we don't get more channels
+         * than what we have registered.
+         */
+        BUG_ON(req->n_channels > WL1271_MAX_CHANNELS);
+
         if (wl->scan.state != WL1271_SCAN_STATE_IDLE)
                 return -EBUSY;
 
@@ -304,10 +309,8 @@ int wl1271_scan(struct wl1271 *wl, const u8 *ssid, size_t ssid_len,
         }
 
         wl->scan.req = req;
+        memset(wl->scan.scanned_ch, 0, sizeof(wl->scan.scanned_ch));
 
-        wl->scan.scanned_ch = kcalloc(req->n_channels,
-                                      sizeof(*wl->scan.scanned_ch),
-                                      GFP_KERNEL);
         /* we assume failure so that timeout scenarios are handled correctly */
         wl->scan.failed = true;
         ieee80211_queue_delayed_work(wl->hw, &wl->scan_complete_work,
diff --git a/drivers/net/wireless/wl12xx/wl12xx.h b/drivers/net/wireless/wl12xx/wl12xx.h
index b04481aadf9c..ba98e1853842 100644
--- a/drivers/net/wireless/wl12xx/wl12xx.h
+++ b/drivers/net/wireless/wl12xx/wl12xx.h
@@ -302,9 +302,10 @@ struct wl1271_rx_mem_pool_addr {
         u32 addr_extra;
 };
 
+#define WL1271_MAX_CHANNELS 64
 struct wl1271_scan {
         struct cfg80211_scan_request *req;
-        bool *scanned_ch;
+        unsigned long scanned_ch[BITS_TO_LONGS(WL1271_MAX_CHANNELS)];
         bool failed;
         u8 state;
         u8 ssid[IW_ESSID_MAX_SIZE+1];