[Intel-gfx] [PATCH] [v3] drm/i915/bdw: Always issue a force restore

[Ben Widawsky]

The PDPs seem to get screwed up otherwise, specifically PDP0. I am not
really clear why this is required, it just works with full PPGTT.

v2: Only do it for gen8, to limit regression potential

v3: Fix the bugzilla links

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=78891
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=78935
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=78936
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=78937
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=78938

Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
---
 drivers/gpu/drm/i915/i915_gem_context.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index 3ffe308..c5330ab 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -568,6 +568,9 @@ mi_set_context(struct intel_engine_cs *ring,
 	else
 		intel_ring_emit(ring, MI_NOOP);
 
+	if (INTEL_INFO(ring->dev)->gen == 8)
+		hw_flags |= MI_FORCE_RESTORE;
+
 	intel_ring_emit(ring, MI_NOOP);
 	intel_ring_emit(ring, MI_SET_CONTEXT);
 	intel_ring_emit(ring, i915_gem_obj_ggtt_offset(new_context->obj) |
-- 
1.9.3