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    Subjecthibernate event order question

    for some time now I had the problem that after a suspend to disk
    network connectivitiy was down and also wake-on-lan would not work.

    First a bit of information, for the real question please see (*)

    Now I just found the ethtool -d (register dump) option
    and decided I want to try to debug this long-standing bug:

    I already found out why network connectivity is down after resume:

    The interfaces eth0 and eth1 are bridged into br0.
    The bridging code sets the interfaces into promiscous mode, but this
    is not properly restored after resume.
    This bug is easily fixable by calling nv_set_multicast(dev) either
    from within nv_open() or after nv_open() in nv_resume().

    The second problem (does not wol after s2disk) is still unsolved
    though. However I have found that wake-on-lan works fine if I
    "rmmod forcedeth" before suspending. This is even a usable
    workaround for me, since the bridge device stays configured and I
    just have to reload forcedeth and readd the interfaces to the bridge
    after resume.

    Now for my question:
    AFAICS the ordering of events is as follows:
    1) User reqests hibernate
    2) Tasks are frozen
    3) Device suspend callbacks get called
    4) Device resume callbacks get called
    5) Memory image is written to disk

    Now, the problem I see with this is that while step 3) prepares the
    device for suspend (and wake-on-lan), step 4) may undo some of this

    In my case, I think the fix for the first bug (promiscous mode does
    not get restored on resume) breaks wake-on-lan (since the new value
    of NvRegPacketFilterFlags may be incompatible with wake-on-lan).

    Shouldn't there be a 'prepare for poweroff'-callback, which gets called
    before the system is powered off for real?

    --- linux-2.6.26-rc2/drivers/net/forcedeth.c 2008-05-17 14:22:06.000000000 +0200
    +++ linux-2.6.26-rc2/drivers/net/forcedeth.c 2008-05-17 19:48:56.000000000 +0200
    @@ -5823,6 +5823,7 @@
    writel(txreg, base + NvRegTransmitPoll);

    rc = nv_open(dev);
    + nv_set_multicast(dev);
    return rc;
    Tobias PGP:

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      Last update: 2008-05-17 19:53    [W:0.024 / U:0.220 seconds]
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