drm/radeon: fix init ordering for r600+

The vram scratch buffer needs to be initialized
before the mc is programmed otherwise we program
0 as the GPU address of the default GPU fault
page.  In most cases we put vram at zero anyway and
reserve a page for the legacy vga buffer so in practice
this shouldn't cause any problems, but better to make
it correct.

Was changed in:
6fab3febf6d949b0a12b1e4e73db38e4a177a79e

Reported-by: FrankR Huang <FrankR.Huang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
diff --git a/drivers/gpu/drm/radeon/si.c b/drivers/gpu/drm/radeon/si.c
index 89393ed..fe8bca6 100644
--- a/drivers/gpu/drm/radeon/si.c
+++ b/drivers/gpu/drm/radeon/si.c
@@ -6343,6 +6343,11 @@
 	/* enable aspm */
 	si_program_aspm(rdev);
 
+	/* scratch needs to be initialized before MC */
+	r = r600_vram_scratch_init(rdev);
+	if (r)
+		return r;
+
 	si_mc_program(rdev);
 
 	if (!rdev->me_fw || !rdev->pfp_fw || !rdev->ce_fw ||
@@ -6360,10 +6365,6 @@
 		return r;
 	}
 
-	r = r600_vram_scratch_init(rdev);
-	if (r)
-		return r;
-
 	r = si_pcie_gart_enable(rdev);
 	if (r)
 		return r;