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    SubjectRe: [PATCH]: In kernel hibernation, suspend to both
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    "Rafael J. Wysocki" <rjw@sisk.pl> wrote:

    >On Wednesday, May 09, 2012, Bojan Smojver wrote:
    >> On Wed, 2012-05-09 at 13:40 +0530, Srivatsa S. Bhat wrote:
    >> > > + error = suspend_devices_and_enter(PM_SUSPEND_MEM);
    >> >
    >> >
    >> > I can imagine running into a host of problems here, since the
    >suspend
    >> > sequence is not carried out fully, from the beginning.
    >> >
    >> > For example, this will skip sending out the PM_SUSPEND_PREPARE and
    >the
    >> > PM_POST_SUSPEND notifiers. Worse, we actually send out the
    >> > PM_HIBERNATION_PREPARE
    >> > and PM_POST_HIBERNATION notifiers and then do a suspend instead,
    >> > underneath!
    >> >
    >> > (Similar cases for the rest of the notifiers sent during suspend vs
    >> > hibernation).
    >> >
    >> > Don't we need to handle such things properly, in order to make
    >> > suspend-to-both
    >> > work reliably?
    >>
    >> Honest answer - I have absolutely no idea. I've seen the code of
    >> suspend-utils (i.e. user mode stuff) and it seems to me that it does
    >> exactly this. Could be wrong of course, just like many times before.
    >>
    >> Rafael?
    >
    >Sorry, that has fallen out of my radar somehow.
    >
    >Srivatsa is right, we should generally pay attention to those details.
    >
    >I think we should generally use a different "prepare" notification for
    >the
    >save-image-and-suspend case.
    >
    >Thanks,
    >Rafael


    OK, I will try to rework then, if that is the case.

    What I don't understand is this: should the hibernation fail for some reason, we would get the same hibernation code unwind that failure, right? So, a suspend after the image write will be just one long "failure", after which hibernation code has to unwind again. No?

    --
    Bojan


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