wl1271: Add handling for failing hardware scan command

Currently, the driver does not handle a failing hardware command to scan in
any way - effectively, the scan machine will jam until the driver is shut down,
and future scan requests will just return -EBUSY to user space, resulting in
a type of busy-loop. The same problem occurs if the firmware fails to deliver
the scan completion event - add timeout for this.

Signed-off-by: Juuso Oikarinen <juuso.oikarinen@nokia.com>
Reviewed-by: Teemu Paasikivi <ext-teemu.3.paasikivi@nokia.com>
Signed-off-by: Luciano Coelho <luciano.coelho@nokia.com>

4 files changed, 32 insertions, 7 deletions

diff --git a/drivers/net/wireless/wl12xx/wl1271.h b/drivers/net/wireless/wl12xx/wl1271.h
index 3576c1cb067f..cae489300e06 100644
--- a/drivers/net/wireless/wl12xx/wl1271.h
+++ b/drivers/net/wireless/wl12xx/wl1271.h
@@ -296,6 +296,7 @@ struct wl1271_rx_mem_pool_addr {
 struct wl1271_scan {
         struct cfg80211_scan_request *req;
         bool *scanned_ch;
+        bool failed;
         u8 state;
         u8 ssid[IW_ESSID_MAX_SIZE+1];
         size_t ssid_len;
@@ -419,7 +420,7 @@ struct wl1271 {
 
         /* Are we currently scanning */
         struct wl1271_scan scan;
-        struct work_struct scan_complete_work;
+        struct delayed_work scan_complete_work;
 
         /* Our association ID */
         u16 aid;
diff --git a/drivers/net/wireless/wl12xx/wl1271_main.c b/drivers/net/wireless/wl12xx/wl1271_main.c
index fecb0c313a1d..c13175892960 100644
--- a/drivers/net/wireless/wl12xx/wl1271_main.c
+++ b/drivers/net/wireless/wl12xx/wl1271_main.c
@@ -657,8 +657,8 @@ static int wl1271_setup(struct wl1271 *wl)
 
         INIT_WORK(&wl->irq_work, wl1271_irq_work);
         INIT_WORK(&wl->tx_work, wl1271_tx_work);
-        INIT_WORK(&wl->scan_complete_work, wl1271_scan_complete_work);
         INIT_WORK(&wl->recovery_work, wl1271_recovery_work);
+        INIT_DELAYED_WORK(&wl->scan_complete_work, wl1271_scan_complete_work);
 
         return 0;
 }
@@ -1013,7 +1013,7 @@ static void __wl1271_op_remove_interface(struct wl1271 *wl)
 
         mutex_unlock(&wl->mutex);
 
-        cancel_work_sync(&wl->scan_complete_work);
+        cancel_delayed_work_sync(&wl->scan_complete_work);
         cancel_work_sync(&wl->irq_work);
         cancel_work_sync(&wl->tx_work);
         cancel_delayed_work_sync(&wl->pspoll_work);
diff --git a/drivers/net/wireless/wl12xx/wl1271_scan.c b/drivers/net/wireless/wl12xx/wl1271_scan.c
index 20caceba435e..37f9ccbe738f 100644
--- a/drivers/net/wireless/wl12xx/wl1271_scan.c
+++ b/drivers/net/wireless/wl12xx/wl1271_scan.c
@@ -30,8 +30,11 @@
 
 void wl1271_scan_complete_work(struct work_struct *work)
 {
-        struct wl1271 *wl =
-                container_of(work, struct wl1271, scan_complete_work);
+        struct delayed_work *dwork;
+        struct wl1271 *wl;
+
+        dwork = container_of(work, struct delayed_work, work);
+        wl = container_of(dwork, struct wl1271, scan_complete_work);
 
         wl1271_debug(DEBUG_SCAN, "Scanning complete");
 
@@ -48,6 +51,11 @@ void wl1271_scan_complete_work(struct work_struct *work)
         mutex_unlock(&wl->mutex);
 
         ieee80211_scan_completed(wl->hw, false);
+
+        if (wl->scan.failed) {
+                wl1271_info("Scan completed due to error.");
+                ieee80211_queue_work(wl->hw, &wl->recovery_work);
+        }
 }
 
 
@@ -191,7 +199,7 @@ out:
 
 void wl1271_scan_stm(struct wl1271 *wl)
 {
-        int ret;
+        int ret = 0;
 
         switch (wl->scan.state) {
         case WL1271_SCAN_STATE_IDLE:
@@ -241,13 +249,22 @@ void wl1271_scan_stm(struct wl1271 *wl)
                 break;
 
         case WL1271_SCAN_STATE_DONE:
-                ieee80211_queue_work(wl->hw, &wl->scan_complete_work);
+                wl->scan.failed = false;
+                cancel_delayed_work(&wl->scan_complete_work);
+                ieee80211_queue_delayed_work(wl->hw, &wl->scan_complete_work,
+                                             msecs_to_jiffies(0));
                 break;
 
         default:
                 wl1271_error("invalid scan state");
                 break;
         }
+
+        if (ret < 0) {
+                cancel_delayed_work(&wl->scan_complete_work);
+                ieee80211_queue_delayed_work(wl->hw, &wl->scan_complete_work,
+                                             msecs_to_jiffies(0));
+        }
 }
 
 int wl1271_scan(struct wl1271 *wl, const u8 *ssid, size_t ssid_len,
@@ -270,6 +287,11 @@ int wl1271_scan(struct wl1271 *wl, const u8 *ssid, size_t ssid_len,
         wl->scan.scanned_ch = kzalloc(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,
+                                     msecs_to_jiffies(WL1271_SCAN_TIMEOUT));
+
         wl1271_scan_stm(wl);
 
         return 0;
diff --git a/drivers/net/wireless/wl12xx/wl1271_scan.h b/drivers/net/wireless/wl12xx/wl1271_scan.h
index 1404e00dc963..bb7af2a102fa 100644
--- a/drivers/net/wireless/wl12xx/wl1271_scan.h
+++ b/drivers/net/wireless/wl12xx/wl1271_scan.h
@@ -46,6 +46,8 @@ void wl1271_scan_complete_work(struct work_struct *work);
 #define WL1271_SCAN_BAND_5_GHZ 1
 #define WL1271_SCAN_PROBE_REQS 3
 
+#define WL1271_SCAN_TIMEOUT    10000 /* msec */
+
 enum {
         WL1271_SCAN_STATE_IDLE,
         WL1271_SCAN_STATE_2GHZ_ACTIVE,