Re: [PATCH] PCI: Only enable IO window if supported

[Guenter Roeck]

Hi Lorenzo,

On 07/07/2015 07:40 AM, Lorenzo Pieralisi wrote:
> On Fri, Jun 19, 2015 at 05:24:13PM +0100, Lorenzo Pieralisi wrote:
> > Hi Guenter,
> >
> > On Thu, Jun 18, 2015 at 07:01:03PM +0100, Guenter Roeck wrote:
> > > On Thu, May 28, 2015 at 07:41:12AM -0500, Bjorn Helgaas wrote:
> > > > > > I'd like res->flags to reflect the capabilities of the hardware, not
> > > > > > whether the window is currently enabled.
> > > > > Flag bits seem to be all taken. Could we use IORESOURCE_DISABLED for that
> > > > > purpose, or could that cause conflicts elsewhere ?
> > > >
> > > > Yes, I think IORESOURCE_DISABLED would be appropriate for any I/O windows
> > > > below a host bridge that doesn't support I/O space.
> > > I integrated Lorenzo's patch and tried to get this working.
> >
> > Thanks. How do you want to proceed with this ? Are you taking my patch
> > and post it along with your updated series ? We need to extend test
> > coverage to platforms we could not test on, as you know my series
> > affects all archs but SPARC (I mean it should *not* affect them, this
> > has to be tested though, I do not have the HW needed, your coverage
> > for x86 and PowerPC is great but I do not think it can be deemed
> > sufficient).
> >
> > Please let me know, thanks !
>
> Any comment on this ? I will have to remove the bridge resource claiming
> from my patch according to Ben's concerns for PowerPC, which requires
> a v3.
>
> How do you want me to go on with this ?

Can you send your v3 ?

I didn't submit my latest version because I recalled Ben's objections,
and I never got around asking you if you plan to send a new version
of your patch.

I had to drop the idea of using IORESOURCE_DISABLED; pretty much all
kernel code uses the "!flags" test to identify unused resources.
I tried to change that, but just could not get it to work.
I ended up introducing a new bus flag instead, PCI_BUS_FLAGS_NO_IO,
which works quite nicely since it propagates to child buses.

Thanks,
Guenter

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/