From 0f4706d2740f2a221cd502922b22e522009041d9 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Tue, 18 Mar 2014 14:50:50 +0200 Subject: [PATCH] drm/i915: Disable stolen memory when DMAR is active 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 Reviewed-by: Daniel Vetter Cc: stable@vger.kernel.org Signed-off-by: Jani Nikula --- 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;