From mboxrd@z Thu Jan  1 00:00:00 1970
From: Vitaly Kuznetsov <vkuznets@redhat.com>
Subject: Re: [PATCH net 2/4] hv_netvsc: reset vf_inject on VF removal
Date: Thu, 11 Aug 2016 14:09:53 +0200
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Cc: netdev <netdev@vger.kernel.org>, Haiyang Zhang <haiyangz@microsoft.com>,
 linux-kernel <linux-kernel@vger.kernel.org>,
 "devel@linuxdriverproject.org" <devel@linuxdriverproject.org>
To: Yuval Mintz <Yuval.Mintz@qlogic.com>
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 (Yuval Mintz's message of "Thu, 11 Aug 2016 11:46:18 +0000")
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Yuval Mintz <Yuval.Mintz@qlogic.com> writes:

>> +static void netvsc_inject_enable(struct net_device_context
>> +*net_device_ctx) {
>> +	net_device_ctx->vf_inject = true;
>> +}
>> +
>> +static void netvsc_inject_disable(struct net_device_context
>> +*net_device_ctx) {
>> +	net_device_ctx->vf_inject = false;
>> +
>> +	/* Wait for currently active users to drain out. */
>> +	while (atomic_read(&net_device_ctx->vf_use_cnt) != 0)
>> +		udelay(50);
>> +}
>
> That was already the behavior before, but are you certain you
> want to unconditionally block without any possible timeout?

Yes, this is OK. After PATCH4 of this series there is only one place
which takes the vf_use_cnt (netvsc_recv_callback()) and it is an
interrupt handler, there are no sleepable operations there.

-- 
  Vitaly