net/hyperv: Use wait_event on outstanding sends during device removal

Change the busy-waiting/udelay to wait_event on outstanding sends.

Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h
index 4ffcd57b011b142fd367530ba032b3495a74a657..2857ab078aac1f9940f406f49916706dc3255441 100644 (file)
--- a/drivers/net/hyperv/hyperv_net.h
+++ b/drivers/net/hyperv/hyperv_net.h
@@ -478,6 +478,7 @@ struct netvsc_device {
        u32 nvsp_version;
 
        atomic_t num_outstanding_sends;
+       wait_queue_head_t wait_drain;
        bool start_remove;
        bool destroy;
        /*

diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index 8b919471472fb1dba4d34ffcf0bfe5b4c723af7b..0c569831db5aeb0de77ef9a4d81d6d7e7f3281b8 100644 (file)
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -42,6 +42,7 @@ static struct netvsc_device *alloc_net_device(struct hv_device *device)
        if (!net_device)
                return NULL;
 
+       init_waitqueue_head(&net_device->wait_drain);
        net_device->start_remove = false;
        net_device->destroy = false;
        net_device->dev = device;
@@ -387,12 +388,8 @@ int netvsc_device_remove(struct hv_device *device)
        spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
 
        /* Wait for all send completions */
-       while (atomic_read(&net_device->num_outstanding_sends)) {
-               dev_info(&device->device,
-                       "waiting for %d requests to complete...\n",
-                       atomic_read(&net_device->num_outstanding_sends));
-               udelay(100);
-       }
+       wait_event(net_device->wait_drain,
+                  atomic_read(&net_device->num_outstanding_sends) == 0);
 
        netvsc_disconnect_vsp(net_device);
 
@@ -486,6 +483,9 @@ static void netvsc_send_completion(struct hv_device *device,
                num_outstanding_sends =
                        atomic_dec_return(&net_device->num_outstanding_sends);
 
+               if (net_device->destroy && num_outstanding_sends == 0)
+                       wake_up(&net_device->wait_drain);
+
                if (netif_queue_stopped(ndev) && !net_device->start_remove &&
                        (hv_ringbuf_avail_percent(&device->channel->outbound)
                        > RING_AVAIL_PERCENT_HIWATER ||