drm/radeon: Ignore RADEON_GEM_GTT_WC on 32-bit x86

commit a08b588e4199e4200d26027ffcdf3ab2fa906412 upstream.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=84627
Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpu/drm/radeon/radeon_object.c b/drivers/gpu/drm/radeon/radeon_object.c
index 480c87d8edc50cc46aad4c612b1f6f4942d9a8a1..835f402a9faf9efbefb8bed3ba3733ec87a21cbd 100644 (file)
--- a/drivers/gpu/drm/radeon/radeon_object.c
+++ b/drivers/gpu/drm/radeon/radeon_object.c
@@ -187,6 +187,13 @@ int radeon_bo_create(struct radeon_device *rdev,
        if (!(rdev->flags & RADEON_IS_PCIE))
                bo->flags &= ~(RADEON_GEM_GTT_WC | RADEON_GEM_GTT_UC);
 
+#ifdef CONFIG_X86_32
+       /* XXX: Write-combined CPU mappings of GTT seem broken on 32-bit
+        * See https://bugs.freedesktop.org/show_bug.cgi?id=84627
+        */
+       bo->flags &= ~RADEON_GEM_GTT_WC;
+#endif
+
        radeon_ttm_placement_from_domain(bo, domain);
        /* Kernel allocation are uninterruptible */
        down_read(&rdev->pm.mclk_lock);