[Intel-gfx] [PATCH 2/4] drm/i915/gtt: Warn if the next layer scratch dma is invalid

[Mika Kuoppala]

When dma page is setup, warn if we try to point the entries
to a uninitialized (zero) dma address. Like we do with gen6

Signed-off-by: Mika Kuoppala <mika.kuoppala at intel.com>
---
 drivers/gpu/drm/i915/i915_gem_gtt.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index 23f5896..78bfb88 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -427,6 +427,8 @@ static void gen8_initialize_pt(struct i915_address_space *vm,
 {
 	gen8_pte_t scratch_pte;
 
+	WARN_ON(px_dma(vm->scratch_page) == 0);
+
 	scratch_pte = gen8_pte_encode(px_dma(vm->scratch_page),
 				      I915_CACHE_LLC, true);
 
@@ -488,6 +490,8 @@ static void gen8_initialize_pd(struct i915_address_space *vm,
 {
 	gen8_pde_t scratch_pde;
 
+	WARN_ON(px_dma(vm->scratch_pt) == 0);
+
 	scratch_pde = gen8_pde_encode(px_dma(vm->scratch_pt), I915_CACHE_LLC);
 
 	fill_px(vm->dev, pd, scratch_pde);
-- 
2.1.4