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    SubjectRe: [PATCH] Re: NAK new drivers without proper power management?
    Hi!

    > > > instead of modifying all drivers to explicitly state that they don't support
    > > > it, we should start with a test of the NULL pointer for .suspend which should
    > > > mean exactly the same without modifying the drivers. I find it obvious that
    > > > a driver which does provide a suspend function will not support it. And if
    > > > some drivers (eg /dev/null) can support it anyway, it's better to change
    > > > *those* drivers to explicitly mark them as compatible.
    > >
    > > No, that doesn't work. In the absence of suspend/resume methods, the PCI
    > > layer will implement basic PM itself. In some cases, this works. In
    > > others, it doesn't. There's no way to automatically determine which is
    > > which without modifying the drivers.
    >
    > Then change the PCI layer to do the basic PM only for known compatible
    > drivers, and modify only the known-compatible drivers to mark them
    > explicitly compatible. IMHO, it generally is a bad idea to require that
    > any driver explicitly states what it *does not* support. It's the reason
    > why users encounter problem on new features with old drivers. For instance,
    > do you know if the old ISA NE2000 driver breaks suspend ? I don't know,
    > but I would at least expect it not to support it by default. It's best
    > to announce what *is* supported and consider everything unimplemented
    > otherwise explicitly stated.

    Actually, ne2k driver is okay. ne2k cards are notoriously buggy, so it
    responds with "****, that damn card has just locked up again, lets
    reset it". Ok, it takes timeout to realize card is "locked up",
    so it could be improved...

    Pavel
    --
    (english) http://www.livejournal.com/~pavelmachek
    (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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