> On Mon, Jul 26, 2021 at 01:36:56PM +0200, Cornelia Huck wrote:
> > On Mon, Jul 26 2021, Srivatsa Vaddagiri <[email protected]> wrote:
> >
> > >> > +indicated by a read of \field{Status} returning 0. Such a device MUST 
> > >> > also
> > >> > fail to accept
> > >> > +FEATURES_OK bit if driver does not negotiate VIRTIO_F_MMIO_RESET_WAIT.
> > >>
> > >> So, this basically means that an older driver that does not know the new
> > >> feature bit will not work with devices offering this bit, even if it did
> > >> poll? This seems acceptable, I just wanted to spell it out.
> > >
> > > Yes I believe that's the desired result. Device has no way to know if 
> > > driver
> > > will poll for reset completion or not unless it accepts the feature.
> > > Are you suggesting we explicitly put in some text in spec to that
> > > effect?
> >
> > Not sure whether it is needed (do others have an opinion?), but probably
> > not.
>
> What about resets before FEATURES_OK? How are these handled?

>From device perspective, it's reset logic will always be same, independent of
when reset was performed by driver (before or after feature negotiation). A
driver that does not wait for reset completion will see undefined behavior after
reset until it discovers that feature negotiation has failed?

- vatsa

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