lkml.org 
[lkml]   [2007]   [Feb]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [RFC][PATCH] Documentation: Ask driver writers to provide suspend/resume support
    Hi!

    > > > +PM support: Since Linux is used on many portable and desktop systems, your
    > > > + driver is likely to be used on such a system and therefore it
    > > > + should support basic power management by implementing, if
    > > > + necessary, the .suspend and .resume methods used during the
    > > > + system-wide suspend and resume transitions. You should verify
    > > > + that your driver correctly handles the suspend and resume, but
    > > > + if you are unable to ensure that, please at least define the
    > > > + .suspend method returning the -ENOSYS ("Function not
    > > > + implemented") error.
    > >
    > > Perhaps pointer to Documentation/power/drivers-testing.txt would be
    > > useful here?
    >
    > Okay, maybe something like this:
    >
    > "Please see Documentation/power/drivers-testing.txt for the driver testing
    > instructions."
    >
    > as the last sentence?

    Looks ok. (BTW you have my ACK).

    > > > +Unfortunately, to effectively test the support for the system-wide suspend and
    > > > +resume transitions in a driver, it is necessary to suspend and resume a fully
    > > > +functional system with this driver loaded. Moreover, that should be done many
    > > > +times, preferably many times in a row, and separately for the suspend to disk
    > > > +(STD) and the suspend to RAM (STR) transitions, because each of these cases
    > > > +involves different ordering of operations and different interactions with the
    > > > +machine's BIOS.
    > >
    > > Hmm, actually it is nice to mix STR + STD, too... and not sure if
    > > "many" is right word... It sounds scary :-).
    >
    > "a couple of"?

    Sounds good.
    > > > +II. Testing the driver
    > > > +
    > > > +Once you have resolved the suspend/resume-related problems with your test system
    > > > +without the new driver, you are ready to test it:
    > > > +
    > > > +1. Build the driver as a module, load it and try the STD in the test mode
    > > > +(cf. 1a)).
    > > > +
    > > > +2. Compile the driver directly into the kernel and try the STD in the test mode
    > > > +(cf. 1a)).
    > > > +
    > > > +3. Build the driver as a module, load it and attempt to suspend to disk in the
    > > > +"reboot", "shutdown" and "platform" modes (cf. 1).
    > > > +
    > > > +4. Compile the driver directly into the kernel and attempt to suspend to disk in
    > > > +the "reboot", "shutdown" and "platform" modes (cf. 1).
    > > > +
    > > > +5. Build the driver as a module, load it and attempt to run s2ram (cf. 2).
    > > > +
    > > > +6. Compile the driver directly into the kernel and attempt to run s2ram (cf. 2).
    > > > +
    > > > +Each of the above tests should be repeated several times and if any of them
    > > > +fails, the driver cannot be regarded as suspend/resume-safe.
    > >
    > > Maybe reorder the tests so that poor submitter will not have to do 3
    > > kernel compiles?
    >
    > I thought he would figure out that there's more efficient way. ;-)

    He probably will... but it reads strangely.

    5. Build the driver as a module, load it and attempt to run s2ram. Then
    repeat with driver build-in?

    Hmm, and maybe driver loaded/build in is not a difference for s2ram?

    Pavel

    --
    (english) http://www.livejournal.com/~pavelmachek
    (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
    -
    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: 2007-02-17 12:43    [W:0.024 / U:90.244 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site