Re: SATA resume slowness, e1000 MSI warning

Michael S. Tsirkin
2007-03-11T19:11:13Z

> Quoting Eric W. Biederman <ebiederm@xmission.com>:
> Subject: Re: SATA resume slowness, e1000 MSI warning
>
> "Michael S. Tsirkin" <mst@mellanox.co.il> writes:
>
> >> Rumor has it that some pci devices can't tolerate < 32bit accesses.
> >> Although I have never met one.
> >
> > hopefully not bridge devices?
> >
> >> The two factors together suggest that
> >> for generic code it probably makes sense to operate on 32bit
> >> quantities, and just to ignore the read-only portion.
> >
> > The code for regular devices seems to use 16-bit accesses, so
> > I think it's best to stay consistent. Or do you want to change this too?
>
> If we are stomping rare probabilities we might as well change that too.
> The code to save pci-x state is relatively recent. So it probably just
> hasn't met a problem device yet (assuming they exist).

OK I guess. I gather we assume writing read-only registers has no side effects?
Are there rumors circulating wrt to these?

--
MST