[Intel-gfx] [PATCH v2 for -fixes] drm/i915: Disable stolen memory when DMAR is active

[Jani Nikula]

On Tue, 18 Mar 2014, Daniel Vetter <daniel at ffwll.ch> wrote:
> On Tue, Mar 18, 2014 at 05:48:28PM +0100, Daniel Vetter wrote:
>> On Tue, Mar 18, 2014 at 02:59:04PM +0200, Jani Nikula wrote:
>> > From: Chris Wilson <chris at chris-wilson.co.uk>
>> > 
>> > We have reports of heavy screen corruption if we try to use the stolen
>> > memory reserved by the BIOS whilst the DMA-Remapper is active. This
>> > quirk may be only specific to a few machines or BIOSes, but first lets
>> > apply the big hammer and always disable use of stolen memory when DMAR
>> > is active.
>> > 
>> > v2 by Jani: Rebase on -fixes, only look at intel_iommu_gfx_mapped.
>> > 
>> > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=68535
>> > Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
>> > Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
>> > Signed-off-by: Jani Nikula <jani.nikula at intel.com>
>> > 
>> > ---
>> > 
>> > Daniel, is this the color you want?
>> 
>> Yeah, colour looks shiny ;-) Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>
>
> Correction, cc: stable is missing.

Pushed to -fixes, thanks for the patch (original by Chris) and review.

Jani.


> -Daniel
>
>> > 
>> > Signed-off-by: Jani Nikula <jani.nikula at intel.com>
>> > ---
>> >  drivers/gpu/drm/i915/i915_gem_stolen.c |    7 +++++++
>> >  1 file changed, 7 insertions(+)
>> > 
>> > diff --git a/drivers/gpu/drm/i915/i915_gem_stolen.c b/drivers/gpu/drm/i915/i915_gem_stolen.c
>> > index d58b4e287e32..28d24caa49f3 100644
>> > --- a/drivers/gpu/drm/i915/i915_gem_stolen.c
>> > +++ b/drivers/gpu/drm/i915/i915_gem_stolen.c
>> > @@ -214,6 +214,13 @@ int i915_gem_init_stolen(struct drm_device *dev)
>> >  	struct drm_i915_private *dev_priv = dev->dev_private;
>> >  	int bios_reserved = 0;
>> >  
>> > +#ifdef CONFIG_INTEL_IOMMU
>> > +	if (intel_iommu_gfx_mapped) {
>> > +		DRM_INFO("DMAR active, disabling use of stolen memory\n");
>> > +		return 0;
>> > +	}
>> > +#endif
>> > +
>> >  	if (dev_priv->gtt.stolen_size == 0)
>> >  		return 0;
>> >  
>> > -- 
>> > 1.7.9.5
>> > 
>> 
>> -- 
>> Daniel Vetter
>> Software Engineer, Intel Corporation
>> +41 (0) 79 365 57 48 - http://blog.ffwll.ch
>
> -- 
> Daniel Vetter
> Software Engineer, Intel Corporation
> +41 (0) 79 365 57 48 - http://blog.ffwll.ch
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-- 
Jani Nikula, Intel Open Source Technology Center