From: David Miller <davem@davemloft.net>
To: tejaswit@codeaurora.org
Cc: netdev@vger.kernel.org
Subject: Re: [PATCH net] ipv4: igmp: hold wakelock to prevent delayed reports
Date: Mon, 04 Jun 2018 11:06:40 -0400 (EDT) [thread overview]
Message-ID: <20180604.110640.184022152967598302.davem@davemloft.net> (raw)
In-Reply-To: <20180601140532.GA13253@tejaswit-linux.qualcomm.com>
From: Tejaswi Tanikella <tejaswit@codeaurora.org>
Date: Fri, 1 Jun 2018 19:35:41 +0530
> On receiving a IGMPv2/v3 query, based on max_delay set in the header a
> timer is started to send out a response after a random time within
> max_delay. If the system then moves into suspend state, Report is
> delayed until system wakes up.
>
> In one reported scenario, on arm64 devices, max_delay was set to 10s,
> Reports were consistantly delayed if the timer is scheduled after 5 plus
> seconds.
>
> Hold wakelock while starting the timer to prevent moving into suspend
> state.
>
> Signed-off-by: Tejaswi Tanikella <tejaswit@codeaurora.org>
As Florian stated, this won't be the only networking facility to hit
a problem like this. So, if we go down this route, we probably want
to generically solve this.
But I have a deeper concern.
Do we really want every timer based querying mechanism to prevent a
system from being able to suspend?
We get to the point where external entities can generate traffic which
can prevent a remote system from entering suspend state.
next prev parent reply other threads:[~2018-06-04 15:06 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-01 14:05 [PATCH net] ipv4: igmp: hold wakelock to prevent delayed reports Tejaswi Tanikella
2018-06-01 14:45 ` Florian Fainelli
2018-06-04 15:03 ` Tejaswi Tanikella
2018-06-04 15:06 ` David Miller [this message]
2018-06-06 14:38 ` Tejaswi Tanikella
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