On Mon, Aug 16, 2021 at 07:04:51PM +0530, Srivatsa Vaddagiri wrote:
> * Michael S. Tsirkin <> [2021-08-16 07:48:56]:
>
> > On Mon, Aug 16, 2021 at 12:05:50PM +0530, Srivatsa Vaddagiri wrote:
> > > * Michael S. Tsirkin <> [2021-08-16 01:35:46]:
> > >
> > > > So thinking about all this, quite early in the setup process we
> > > > have:
> > > >
> > > > /* Figure out what features the device supports. */
> > > > device_features = dev->config->get_features(dev);
> > > >
> > > >
> > > > isn't this sufficient? this will flush out
> > > > all writes and device can defer responding to reads
> > > > until reset is complete.
> > >
> > > Hmm not sure if that's possible in all MMIO devices? I think a while back Jason
> > > felt some of the MMIO devices, their registers could act as plain DRAM for
> > > reads, which means device can't block such reads?
> > >
> > > - vatsa
> >
> > Is it worth bothering about theoretical issues though? Jason what is
> > your take?
>
> What about the case where device reset fails, which may require driver to
> initiate reset again or give up on device? Won't the read of features be forever
> deferred in that case?
>
> - vatsa
That might be worth addressing but I feel your proposal does not
address it sufficiently.
> ---
>
> Qualcomm Innovation Center, Inc. is submitting the attached "feedback" as a
> non-member to the virtio-dev mailing list for consideration and inclusion.
