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

[Jani Nikula]

On Fri, 05 Dec 2014, Daniel Vetter <daniel at 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 at 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 at intel.com>
>> > Signed-off-by: Daniel Vetter <daniel.vetter at 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 at 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 at users.sourceforge.net> 
> Cc: stable at vger.kernel.org
>
> This regression goes back to
>
> commit eaba1b8f3379b5d100bd146b9a41d28348bdfd09
> Author: Chris Wilson <chris at 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