Re: [PATCH] drm/i915: Don't complain about stolen conflicts on gen3

Jani Nikula
2014-12-08T12:46:44Z

On Fri, 05 Dec 2014, Daniel Vetter <daniel@ffwll.ch> wrote:
> On Fri, Dec 05, 2014 at 10:30:47AM -0800, Jesse Barnes wrote:
>> On Fri, 11 Apr 2014 15:55:17 +0200
>> Daniel Vetter <daniel.vetter@ffwll.ch> wrote:
>>
>> > Apparently stuff works that way on those machines.
>> >
>> > I agree with Chris' concern that this is a bit risky but imo worth a
>> > shot in -next just for fun. Afaics all these machines have the pci
>> > resources allocated like that by the BIOS, so I suspect that it's all
>> > ok.
>> >
>> > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=76983
>> > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=71031
>> > Tested-by: lu hua <huax.lu@intel.com>
>> > Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
>> > ---
>> > drivers/gpu/drm/i915/i915_gem_stolen.c | 6 +++++-
>> > 1 file changed, 5 insertions(+), 1 deletion(-)
>> >
>> > diff --git a/drivers/gpu/drm/i915/i915_gem_stolen.c
>> > b/drivers/gpu/drm/i915/i915_gem_stolen.c index
>> > 62ef55ba061c..99d147af173a 100644 ---
>> > a/drivers/gpu/drm/i915/i915_gem_stolen.c +++
>> > b/drivers/gpu/drm/i915/i915_gem_stolen.c @@ -93,7 +93,11 @@ static
>> > unsigned long i915_stolen_to_physical(struct drm_device *dev) r =
>> > devm_request_mem_region(dev->dev, base + 1, dev_priv->gtt.stolen_size
>> > - 1, "Graphics Stolen Memory");
>> > - if (r == NULL) {
>> > + /*
>> > + * GEN3 firmware likes to smash pci bridges into the
>> > stolen
>> > + * range. Apparently this works.
>> > + */
>> > + if (r == NULL && !IS_GEN3(dev)) {
>> > DRM_ERROR("conflict detected with stolen
>> > region: [0x%08x - 0x%08x]\n", base, base +
>> > (uint32_t)dev_priv->gtt.stolen_size); base = 0;
>>
>>
>> Yeah just to allay fears: the decode priority on the GMCH is fixed and
>> specific. The stolen range is demarcated by some regs which the GMCH
>> decodes before it tries going out into PCI space. So it's safe to see
>> the stolen range under the bus0 window (probably even under some device
>> window down the range) but does make things messier for us.
>>
>> Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
>>
>> Looks like the reporter gave a t-b too.
>
> The other t-b from the other bugzilla is missing though:
>
> Tested-by: Paul Menzel <paulepanter@users.sourceforge.net>
> Cc: stable@vger.kernel.org
>
> This regression goes back to
>
> commit eaba1b8f3379b5d100bd146b9a41d28348bdfd09
> Author: Chris Wilson <chris@chris-wilson.co.uk>
> Date: Thu Jul 4 12:28:35 2013 +0100
>
> drm/i915: Verify that our stolen memory doesn't conflict
>
> Jani, can you please pick this up for 3.19?

Pushed to drm-intel-next-fixes, thanks for the patch and review.

BR,
Jani.

>
> Thanks, Daniel
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> +41 (0) 79 365 57 48 - http://blog.ffwll.ch

--
Jani Nikula, Intel Open Source Technology Center