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

[Guenter Roeck]

On 07/07/2015 10:28 AM, Lorenzo Pieralisi wrote:
> On Tue, Jul 07, 2015 at 04:01:45PM +0100, Guenter Roeck wrote:
> > 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 ?
>
> Yes, I have to figure out though where I can claim bridge resources
> on PROBE_ONLY arm/arm64 systems, which is proving interesting, anyway
> I will send it out asap.
>
> > 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.
>
> No worries, let's get this sorted.
>
> > 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.
>
> Ok, great, I can test it too.

I just sent out the curent version of my patch as RFC to get some feedback.
I'll be out of the office for the next two weeks, so I won't be able
to do much if any testing during that time. So take time for your v3.

Thanks,
Guenter

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