lkml.org 
[lkml]   [2007]   [May]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    SubjectRe: [RFC][PATCH -mm 3/3] PM: Disable _request_firmware before hibernation/suspend
    Date
    On Sunday, 27 May 2007 23:49, Kay Sievers wrote:
    > On 5/27/07, Matthew Garrett <mjg59@srcf.ucam.org> wrote:
    > > On Sun, May 27, 2007 at 10:31:53PM +0200, Rafael J. Wysocki wrote:
    > > > From: Rafael J. Wysocki <rjw@sisk.pl>
    > > >
    > > > 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.

    Greetings,
    Rafael
    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2007-05-27 23:57    [W:0.022 / U:4.240 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site