drm/i915: Check engine->default_state mapping on module load

Check we can indeed acquire a WB mapping of the context image on module
load. Later this will give us the opportunity to validate that we can
switch from WC to WB as required.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180914123504.2062-2-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 89834ce..d276fb3 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -5416,6 +5416,7 @@ static int __intel_engines_record_defaults(struct drm_i915_private *i915)
 
        for_each_engine(engine, i915, id) {
                struct i915_vma *state;
+               void *vaddr;
 
                state = to_intel_context(ctx, engine)->state;
                if (!state)
@@ -5438,6 +5439,16 @@ static int __intel_engines_record_defaults(struct drm_i915_private *i915)
                        goto err_active;
 
                engine->default_state = i915_gem_object_get(state->obj);
+
+               /* Check we can acquire the image of the context state */
+               vaddr = i915_gem_object_pin_map(engine->default_state,
+                                               I915_MAP_WB);
+               if (IS_ERR(vaddr)) {
+                       err = PTR_ERR(vaddr);
+                       goto err_active;
+               }
+
+               i915_gem_object_unpin_map(engine->default_state);
        }
 
        if (IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM)) {