[Intel-gfx] [PATCH v2] drm/i915/dpt: Use shmem for dpt objects

[Radhakrishna Sripada]

Dpt objects that are created from internal get evicted when there is
memory pressure and do not get restored when pinned during scanout. The
pinned page table entries look corrupted and programming the display
engine with the incorrect pte's result in DE throwing pipe faults.

Create DPT objects from shmem and mark the object as dirty when pinning so
that the object is restored when shrinker evicts an unpinned buffer object.

v2: Unconditionally mark the dpt objects dirty during pinning(Chris).

Fixes: 0dc987b699ce ("drm/i915/display: Add smem fallback allocation for dpt")
Cc: <stable at vger.kernel.org> # v6.0+
Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin at linux.intel.com>
Suggested-by: Chris Wilson <chris.p.wilson at intel.com>
Signed-off-by: Fei Yang <fei.yang at intel.com>
Signed-off-by: Radhakrishna Sripada <radhakrishna.sripada at intel.com>
---
 drivers/gpu/drm/i915/display/intel_dpt.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/display/intel_dpt.c b/drivers/gpu/drm/i915/display/intel_dpt.c
index 7c5fddb203ba..fbfd8f959f17 100644
--- a/drivers/gpu/drm/i915/display/intel_dpt.c
+++ b/drivers/gpu/drm/i915/display/intel_dpt.c
@@ -166,6 +166,8 @@ struct i915_vma *intel_dpt_pin(struct i915_address_space *vm)
 		i915_vma_get(vma);
 	}
 
+	dpt->obj->mm.dirty = true;
+
 	atomic_dec(&i915->gpu_error.pending_fb_pin);
 	intel_runtime_pm_put(&i915->runtime_pm, wakeref);
 
@@ -261,7 +263,7 @@ intel_dpt_create(struct intel_framebuffer *fb)
 		dpt_obj = i915_gem_object_create_stolen(i915, size);
 	if (IS_ERR(dpt_obj) && !HAS_LMEM(i915)) {
 		drm_dbg_kms(&i915->drm, "Allocating dpt from smem\n");
-		dpt_obj = i915_gem_object_create_internal(i915, size);
+		dpt_obj = i915_gem_object_create_shmem(i915, size);
 	}
 	if (IS_ERR(dpt_obj))
 		return ERR_CAST(dpt_obj);
-- 
2.34.1