On Wed, Mar 05, 2014 at 04:17:17PM +0100, Daniel Vetter wrote: > On Fri, Feb 28, 2014 at 12:14:02PM +0000, Chris Wilson wrote: > > 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. > > > > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=68535 > > Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > > Cc: Daniel Vetter <daniel.vetter@xxxxxxxx> > > --- > > drivers/gpu/drm/i915/i915_gem_stolen.c | 14 ++++++++++++++ > > 1 file changed, 14 insertions(+) > > > > diff --git a/drivers/gpu/drm/i915/i915_gem_stolen.c b/drivers/gpu/drm/i915/i915_gem_stolen.c > > index 984ada1b0084..13a849afe479 100644 > > --- a/drivers/gpu/drm/i915/i915_gem_stolen.c > > +++ b/drivers/gpu/drm/i915/i915_gem_stolen.c > > @@ -325,11 +325,25 @@ void i915_gem_cleanup_stolen(struct drm_device *dev) > > drm_mm_takedown(&dev_priv->mm.stolen); > > } > > > > +static bool need_dmar_wa(struct drm_device *dev) > > +{ > > +#ifdef CONFIG_INTEL_IOMMU > > + if (INTEL_INFO(dev)->gen >= 6 && intel_iommu_gfx_mapped) > > Why the gen check in here? Without that we could just check > intel_iommu_gfx_mapped and shovel the #ifdef into stolen init. No need to > spread it out like that imo. It's almost as if it was cut'n'paste from another VTd w/a. I'm worried that this is too big a hammer. I would have expected more complaints if VTd was this broken since 3.9. Otoh, it is a severe bug. -chris -- Chris Wilson, Intel Open Source Technology Centre _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
