| From 0f4706d2740f2a221cd502922b22e522009041d9 Mon Sep 17 00:00:00 2001 |
| From: Chris Wilson <chris@chris-wilson.co.uk> |
| Date: Tue, 18 Mar 2014 14:50:50 +0200 |
| Subject: drm/i915: Disable stolen memory when DMAR is active |
| |
| From: Chris Wilson <chris@chris-wilson.co.uk> |
| |
| commit 0f4706d2740f2a221cd502922b22e522009041d9 upstream. |
| |
| 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@chris-wilson.co.uk> |
| Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> |
| Signed-off-by: Jani Nikula <jani.nikula@intel.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| drivers/gpu/drm/i915/i915_gem_stolen.c | 7 +++++++ |
| 1 file changed, 7 insertions(+) |
| |
| --- a/drivers/gpu/drm/i915/i915_gem_stolen.c |
| +++ b/drivers/gpu/drm/i915/i915_gem_stolen.c |
| @@ -201,6 +201,13 @@ int i915_gem_init_stolen(struct drm_devi |
| 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; |
| |
