staging: brcm80211: use wait queues instead of semaphores in wl_cfg80211.c

In wl_cfg80211.c two semaphores were used to trigger a task to process
an event. The wait queues are better suited for that purpose. This also
removes checkpatch warning on sema_init() calls in this source file.

Reviewed-by: Roland Vossen <rvossen@broadcom.com>
Reviewed-by: Franky Lin <frankyl@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/staging/brcm80211/brcmfmac/wl_cfg80211.c b/drivers/staging/brcm80211/brcmfmac/wl_cfg80211.c
index bc1e1a9..833defb 100644 (file)
--- a/drivers/staging/brcm80211/brcmfmac/wl_cfg80211.c
+++ b/drivers/staging/brcm80211/brcmfmac/wl_cfg80211.c
@@ -3162,7 +3162,7 @@ static void brcmf_deinit_priv_mem(struct brcmf_cfg80211_priv *cfg_priv)
 
 static s32 brcmf_create_event_handler(struct brcmf_cfg80211_priv *cfg_priv)
 {
-       sema_init(&cfg_priv->event_sync, 0);
+       init_waitqueue_head(&cfg_priv->event_waitq);
        cfg_priv->event_tsk = kthread_run(brcmf_event_handler, cfg_priv,
                                          "wl_event_handler");
        if (IS_ERR(cfg_priv->event_tsk)) {
@@ -3224,7 +3224,7 @@ static s32 brcmf_wakeup_iscan(struct brcmf_cfg80211_iscan_ctrl *iscan)
 {
        if (likely(iscan->state != WL_ISCAN_STATE_IDLE)) {
                WL_SCAN("wake up iscan\n");
-               up(&iscan->sync);
+               wake_up(&iscan->waitq);
                return 0;
        }
 
@@ -3330,13 +3330,19 @@ static s32 brcmf_iscan_thread(void *data)
                        (struct brcmf_cfg80211_iscan_ctrl *)data;
        struct brcmf_cfg80211_priv *cfg_priv = iscan_to_cfg(iscan);
        struct brcmf_cfg80211_iscan_eloop *el = &iscan->el;
+       DECLARE_WAITQUEUE(wait, current);
        u32 status;
        int err = 0;
 
        sched_setscheduler(current, SCHED_FIFO, &param);
        allow_signal(SIGTERM);
        status = BRCMF_SCAN_RESULTS_PARTIAL;
-       while (likely(!down_interruptible(&iscan->sync))) {
+       add_wait_queue(&iscan->waitq, &wait);
+       while (1) {
+               prepare_to_wait(&iscan->waitq, &wait, TASK_INTERRUPTIBLE);
+
+               schedule();
+
                if (kthread_should_stop())
                        break;
                if (iscan->timer_on) {
@@ -3353,6 +3359,7 @@ static s32 brcmf_iscan_thread(void *data)
                rtnl_unlock();
                el->handler[status](cfg_priv);
        }
+       finish_wait(&iscan->waitq, &wait);
        if (iscan->timer_on) {
                del_timer_sync(&iscan->timer);
                iscan->timer_on = 0;
@@ -3380,7 +3387,7 @@ static s32 brcmf_invoke_iscan(struct brcmf_cfg80211_priv *cfg_priv)
 
        if (cfg_priv->iscan_on && !iscan->tsk) {
                iscan->state = WL_ISCAN_STATE_IDLE;
-               sema_init(&iscan->sync, 0);
+               init_waitqueue_head(&iscan->waitq);
                iscan->tsk = kthread_run(brcmf_iscan_thread, iscan, "wl_iscan");
                if (IS_ERR(iscan->tsk)) {
                        WL_ERR("Could not create iscan thread\n");
@@ -3528,7 +3535,7 @@ void brcmf_cfg80211_detach(void)
 
 static void brcmf_wakeup_event(struct brcmf_cfg80211_priv *cfg_priv)
 {
-       up(&cfg_priv->event_sync);
+       wake_up(&cfg_priv->event_waitq);
 }
 
 static s32 brcmf_event_handler(void *data)
@@ -3537,27 +3544,39 @@ static s32 brcmf_event_handler(void *data)
                        (struct brcmf_cfg80211_priv *)data;
        struct sched_param param = {.sched_priority = MAX_RT_PRIO - 1 };
        struct brcmf_cfg80211_event_q *e;
+       DECLARE_WAITQUEUE(wait, current);
 
        sched_setscheduler(current, SCHED_FIFO, &param);
        allow_signal(SIGTERM);
-       while (likely(!down_interruptible(&cfg_priv->event_sync))) {
+       add_wait_queue(&cfg_priv->event_waitq, &wait);
+       while (1) {
+               prepare_to_wait(&cfg_priv->event_waitq, &wait,
+                               TASK_INTERRUPTIBLE);
+
+               schedule();
+
                if (kthread_should_stop())
                        break;
+
                e = brcmf_deq_event(cfg_priv);
                if (unlikely(!e)) {
                        WL_ERR("event queue empty...\n");
-                       BUG();
+                       continue;
                }
-               WL_INFO("event type (%d)\n", e->etype);
-               if (cfg_priv->el.handler[e->etype])
-                       cfg_priv->el.handler[e->etype](cfg_priv,
-                                                      cfg_to_ndev(cfg_priv),
-                                                      &e->emsg, e->edata);
-               else
-                       WL_INFO("Unknown Event (%d): ignoring\n", e->etype);
 
-               brcmf_put_event(e);
+               do {
+                       WL_INFO("event type (%d)\n", e->etype);
+                       if (cfg_priv->el.handler[e->etype])
+                               cfg_priv->el.handler[e->etype](cfg_priv,
+                                       cfg_to_ndev(cfg_priv),
+                                       &e->emsg, e->edata);
+                       else
+                               WL_INFO("Unknown Event (%d): ignoring\n",
+                                       e->etype);
+                       brcmf_put_event(e);
+               } while ((e = brcmf_deq_event(cfg_priv)));
        }
+       finish_wait(&cfg_priv->event_waitq, &wait);
        WL_INFO("was terminated\n");
        return 0;
 }

diff --git a/drivers/staging/brcm80211/brcmfmac/wl_cfg80211.h b/drivers/staging/brcm80211/brcmfmac/wl_cfg80211.h
index ff5c19a..049138b 100644 (file)
--- a/drivers/staging/brcm80211/brcmfmac/wl_cfg80211.h
+++ b/drivers/staging/brcm80211/brcmfmac/wl_cfg80211.h
@@ -249,7 +249,7 @@ struct brcmf_cfg80211_iscan_ctrl {
        u32 timer_on;
        s32 state;
        struct task_struct *tsk;
-       struct semaphore sync;
+       wait_queue_head_t waitq;
        struct brcmf_cfg80211_iscan_eloop el;
        void *data;
        s8 ioctl_buf[BRCMF_C_IOCTL_SMLEN];
@@ -295,13 +295,12 @@ struct brcmf_cfg80211_priv {
                                                 cfg80211 layer */
        struct brcmf_cfg80211_ie ie;    /* information element object for
                                         internal purpose */
-       struct semaphore event_sync;    /* for synchronization of main event
-                                        thread */
        struct brcmf_cfg80211_profile *profile; /* holding dongle profile */
        struct brcmf_cfg80211_iscan_ctrl *iscan;        /* iscan controller */
        struct brcmf_cfg80211_connect_info conn_info; /* association info */
        struct brcmf_cfg80211_pmk_list *pmk_list;       /* wpa2 pmk list */
        struct task_struct *event_tsk;  /* task of main event handler thread */
+       wait_queue_head_t event_waitq;  /* wait queue for main event handling */
        unsigned long status;           /* current dongle status */
        void *pub;
        u32 channel;            /* current channel */