brcm80211: fmac: fix missing completion events issue
authorFranky Lin <frankyl@broadcom.com>
Mon, 23 Apr 2012 21:24:53 +0000 (14:24 -0700)
committerJohn W. Linville <linville@tuxdriver.com>
Fri, 27 Apr 2012 19:20:39 +0000 (15:20 -0400)
dpc takes care of all data packets transmissions for sdio function
2. It is possible that it misses some completion events when the
traffic is heavy or it's running on a slow cpu. A linked list is
introduced to make sure dpc is invoked whenever needed.

Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Reviewed-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Franky Lin <frankyl@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
drivers/net/wireless/brcm80211/brcmfmac/dhd_sdio.c

index 2bf5dda..eb3829b 100644 (file)
@@ -574,6 +574,8 @@ struct brcmf_sdio {
 
        struct task_struct *dpc_tsk;
        struct completion dpc_wait;
+       struct list_head dpc_tsklst;
+       spinlock_t dpc_tl_lock;
 
        struct semaphore sdsem;
 
@@ -2594,29 +2596,58 @@ clkwait:
        return resched;
 }
 
+static inline void brcmf_sdbrcm_adddpctsk(struct brcmf_sdio *bus)
+{
+       struct list_head *new_hd;
+       unsigned long flags;
+
+       if (in_interrupt())
+               new_hd = kzalloc(sizeof(struct list_head), GFP_ATOMIC);
+       else
+               new_hd = kzalloc(sizeof(struct list_head), GFP_KERNEL);
+       if (new_hd == NULL)
+               return;
+
+       spin_lock_irqsave(&bus->dpc_tl_lock, flags);
+       list_add_tail(new_hd, &bus->dpc_tsklst);
+       spin_unlock_irqrestore(&bus->dpc_tl_lock, flags);
+}
+
 static int brcmf_sdbrcm_dpc_thread(void *data)
 {
        struct brcmf_sdio *bus = (struct brcmf_sdio *) data;
+       struct list_head *cur_hd, *tmp_hd;
+       unsigned long flags;
 
        allow_signal(SIGTERM);
        /* Run until signal received */
        while (1) {
                if (kthread_should_stop())
                        break;
-               if (!wait_for_completion_interruptible(&bus->dpc_wait)) {
-                       /* Call bus dpc unless it indicated down
-                       (then clean stop) */
-                       if (bus->sdiodev->bus_if->state != BRCMF_BUS_DOWN) {
-                               if (brcmf_sdbrcm_dpc(bus))
-                                       complete(&bus->dpc_wait);
-                       } else {
+
+               if (list_empty(&bus->dpc_tsklst))
+                       if (wait_for_completion_interruptible(&bus->dpc_wait))
+                               break;
+
+               spin_lock_irqsave(&bus->dpc_tl_lock, flags);
+               list_for_each_safe(cur_hd, tmp_hd, &bus->dpc_tsklst) {
+                       spin_unlock_irqrestore(&bus->dpc_tl_lock, flags);
+
+                       if (bus->sdiodev->bus_if->state == BRCMF_BUS_DOWN) {
                                /* after stopping the bus, exit thread */
                                brcmf_sdbrcm_bus_stop(bus->sdiodev->dev);
                                bus->dpc_tsk = NULL;
                                break;
                        }
-               } else
-                       break;
+
+                       if (brcmf_sdbrcm_dpc(bus))
+                               brcmf_sdbrcm_adddpctsk(bus);
+
+                       spin_lock_irqsave(&bus->dpc_tl_lock, flags);
+                       list_del(cur_hd);
+                       kfree(cur_hd);
+               }
+               spin_unlock_irqrestore(&bus->dpc_tl_lock, flags);
        }
        return 0;
 }
@@ -2669,8 +2700,10 @@ static int brcmf_sdbrcm_bus_txdata(struct device *dev, struct sk_buff *pkt)
        /* Schedule DPC if needed to send queued packet(s) */
        if (!bus->dpc_sched) {
                bus->dpc_sched = true;
-               if (bus->dpc_tsk)
+               if (bus->dpc_tsk) {
+                       brcmf_sdbrcm_adddpctsk(bus);
                        complete(&bus->dpc_wait);
+               }
        }
 
        return ret;
@@ -3514,8 +3547,10 @@ void brcmf_sdbrcm_isr(void *arg)
                brcmf_dbg(ERROR, "isr w/o interrupt configured!\n");
 
        bus->dpc_sched = true;
-       if (bus->dpc_tsk)
+       if (bus->dpc_tsk) {
+               brcmf_sdbrcm_adddpctsk(bus);
                complete(&bus->dpc_wait);
+       }
 }
 
 static bool brcmf_sdbrcm_bus_watchdog(struct brcmf_sdio *bus)
@@ -3559,8 +3594,10 @@ static bool brcmf_sdbrcm_bus_watchdog(struct brcmf_sdio *bus)
                                bus->ipend = true;
 
                                bus->dpc_sched = true;
-                               if (bus->dpc_tsk)
+                               if (bus->dpc_tsk) {
+                                       brcmf_sdbrcm_adddpctsk(bus);
                                        complete(&bus->dpc_wait);
+                               }
                        }
                }
 
@@ -3897,6 +3934,8 @@ void *brcmf_sdbrcm_probe(u32 regsva, struct brcmf_sdio_dev *sdiodev)
        }
        /* Initialize DPC thread */
        init_completion(&bus->dpc_wait);
+       INIT_LIST_HEAD(&bus->dpc_tsklst);
+       spin_lock_init(&bus->dpc_tl_lock);
        bus->dpc_tsk = kthread_run(brcmf_sdbrcm_dpc_thread,
                                   bus, "brcmf_dpc");
        if (IS_ERR(bus->dpc_tsk)) {