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    SubjectRe: [RFC][PATCH -mm 3/3] PM: Disable _request_firmware before hibernation/suspend
    On Sunday, 27 May 2007 23:49, Kay Sievers wrote:
    > On 5/27/07, Matthew Garrett <> wrote:
    > > On Sun, May 27, 2007 at 10:31:53PM +0200, Rafael J. Wysocki wrote:
    > > > From: Rafael J. Wysocki <>
    > > >
    > > > Use a hibernation and suspend notifier to disable the firmware requesting
    > > > mechanism before a hibernation/suspend and enable it after the operation.
    > >
    > > This avoids the problem of .resume methods calling userspace while
    > > userspace is frozen and a resulting hang, but does it actually result in
    > > the drivers beginning to work again? If we remove process freezing in
    > > STR, this should just work[1] without the need to complicate things. On
    > > the other hand, if we don't want to support these functions in the
    > > suspend and resume methods we could just audit the kernel and remove
    > > them all.
    > What exactly is the problem we see here? The timeout of the firmware loader?
    > What goes wrong with frozen userspace, usually there is only a netlink
    > message sent from the kernel, which should be received and handled
    > just fine when userspace is running again.

    Users report the timeout as a problem and it's not that straightforward to
    figure out what happens.

    Still, I agree it's much better if drivers don't use request_firmware() in
    their .resume() routines at all, because they shouldn't rely upon user land at
    this point.

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