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Subject: Re: [Xen-devel] [PATCH] xen-netfront: wait xenbus state change when
 load module manually
To:     David Miller <davem@davemloft.net>
Cc:     jgross@suse.com, netdev@vger.kernel.org,
        boris.ostrovsky@oracle.com, linux-kernel@vger.kernel.org,
        xen-devel@lists.xenproject.org
References: <20180727095608.25210-1-xiliang@redhat.com>
 <20180729.083040.53901922165497594.davem@davemloft.net>
From:   Xiao Liang <xiliang@redhat.com>
Message-ID: <60e93e09-7dc2-d2f6-379d-c1d086aa1f49@redhat.com>
Date:   Mon, 30 Jul 2018 16:18:10 +0800
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Thanks, David

On 07/29/2018 11:30 PM, David Miller wrote:
> From: Xiao Liang <xiliang@redhat.com>
> Date: Fri, 27 Jul 2018 17:56:08 +0800
>
>> @@ -1330,6 +1331,11 @@ static struct net_device *xennet_create_dev(struct xenbus_device *dev)
>>   	netif_carrier_off(netdev);
>>   
>>   	xenbus_switch_state(dev, XenbusStateInitialising);
>> +	wait_event(module_load_q,
>> +			   xenbus_read_driver_state(dev->otherend) !=
>> +			   XenbusStateClosed &&
>> +			   xenbus_read_driver_state(dev->otherend) !=
>> +			   XenbusStateUnknown);
>>   	return netdev;
>>   
>>    exit:
> What performs the wakeups that will trigger for this sleep site?
In my understanding, backend leaving closed/unknow state can trigger the 
wakeups. I mean to make sure both sides are ready for creating connection.

Thanks,
Liang
>
> Thank you.
>
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