[Intel-gfx] agp/intel: can't ioremap flush page - no chipset flushing

[Bjorn Helgaas]

On Fri, Mar 7, 2014 at 2:03 PM, Paul Bolle <pebolle at tiscali.nl> wrote:
> On Fri, 2014-03-07 at 13:40 -0700, Bjorn Helgaas wrote:
>> It seems quite possible that I broke pci_bus_alloc_resource(), which could
>> cause an allocation failure like this.
>>
>> If you have a chance to try it, here's a debug patch against v3.14-rc5.  It
>> should apply cleanly to 96702be56037.  If you can try it, please attach the
>> dmesg log to the bugzilla.
>
> That ThinkPad X41 is now building 96702be56037. Once that build is
> finished and tested I'll try your debug patch (on top of v3.14-rc5, see
> later). It might take some time to finish both builds and test boots.

> My v3.13 based builds don't have INTEL_GTT set! My v3.14-rcy based
> builds do. I have not yet investigated why that is.

I think that's OK.  CONFIG_INTEL_GTT was added after v3.13
(00fe639a56b4 "drm/i915: Make AGP support optional").  It looks like
in v3.13, intel-gtt.o was built if CONFIG_AGP_INTEL=y (or =m), which
you probably do have (see drivers/char/agp/Makefile).

> Too bad drivers/pci/bus.o is built in by definition. If only one could
> build a kernel without rebuilding all modules. Or is there some way to
> actually do that?

You should be able to "make bzImage" and get just the kernel.  But
there might be module loading issues if the modules don't exactly
match the kernel.  I think it's possible to turn that checking off,
but I don't do it often enough to remember details.

Bjorn