Aggressive suspend vs NM/DHCP

John Gilmore gnu at
Wed Oct 20 17:46:20 EDT 2010

> (nor for the first time) I spot an XO that goes into suspend in the
> middle of the DHCP conversation. In this case, it was with a bad WEP
> key so we never heard back from the DHCP server.
> But if you look at /var/log/messages, you see dhclient's DHCPDISCOVER
> and 12s later PM: Syncing filesystems... done.

Normally you'd get a response from a working DHCP server in much than
12 seconds.

> Do we wake up on broadcast DHCP responses properly? (Am I worrying pointlessly?)

If the client sent a broadcast DHCP request, any response will
NOT be a broadcast -- it'll be sent directly to the MAC address of
the requester.  (I co-designed the BOOTP protocol that DHCP is based on.)

> Otherwise, is there a way for powerd to wait a bit longer when
> NM/dhclient are... active?

I guess I have to post this once a month:  stop dumping more kludges into 
the kludged autosuspend implementation.  If you fix it properly, once,
then you'll never have to kludge anything again.  An autosuspended
laptop should awaken when it gets a packet addressed to it.  Fix all
bugs around that and you won't need kludges.


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