Merge branch 'drm-ttm-unmappable' into drm-core-next

[pandora-kernel.git] / arch / x86 / kernel / aperture_64.c

diff --git a/arch/x86/kernel/aperture_64.c b/arch/x86/kernel/aperture_64.c
index 3704997..b5d8b0b 100644 (file)
--- a/arch/x86/kernel/aperture_64.c
+++ b/arch/x86/kernel/aperture_64.c
@@ -393,6 +393,7 @@ void __init gart_iommu_hole_init(void)
        for (i = 0; i < ARRAY_SIZE(bus_dev_ranges); i++) {
                int bus;
                int dev_base, dev_limit;
+               u32 ctl;
 
                bus = bus_dev_ranges[i].bus;
                dev_base = bus_dev_ranges[i].dev_base;
@@ -406,7 +407,19 @@ void __init gart_iommu_hole_init(void)
                        gart_iommu_aperture = 1;
                        x86_init.iommu.iommu_init = gart_iommu_init;
 
-                       aper_order = (read_pci_config(bus, slot, 3, AMD64_GARTAPERTURECTL) >> 1) & 7;
+                       ctl = read_pci_config(bus, slot, 3,
+                                             AMD64_GARTAPERTURECTL);
+
+                       /*
+                        * Before we do anything else disable the GART. It may
+                        * still be enabled if we boot into a crash-kernel here.
+                        * Reconfiguring the GART while it is enabled could have
+                        * unknown side-effects.
+                        */
+                       ctl &= ~GARTEN;
+                       write_pci_config(bus, slot, 3, AMD64_GARTAPERTURECTL, ctl);
+
+                       aper_order = (ctl >> 1) & 7;
                        aper_size = (32 * 1024 * 1024) << aper_order;
                        aper_base = read_pci_config(bus, slot, 3, AMD64_GARTAPERTUREBASE) & 0x7fff;
                        aper_base <<= 25;