drm/i915: Serialise with engine-pm around requests on the kernel_context
As the engine->kernel_context is used within the engine-pm barrier, we
have to be careful when emitting requests outside of the barrier, as the
strict timeline locking rules do not apply. Instead, we must ensure the
engine_park() cannot be entered as we build the request, which is
simplest by taking an explicit engine-pm wakeref around the request
construction.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191125105858.1718307-1-chris@chris-wilson.co.uk
diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c
index 608e6c3..b46715b 100644
--- a/drivers/gpu/drm/i915/i915_perf.c
+++ b/drivers/gpu/drm/i915/i915_perf.c
@@ -1968,7 +1968,9 @@ static int emit_oa_config(struct i915_perf_stream *stream,
if (err)
goto err_vma_put;
+ intel_engine_pm_get(ce->engine);
rq = i915_request_create(ce);
+ intel_engine_pm_put(ce->engine);
if (IS_ERR(rq)) {
err = PTR_ERR(rq);
goto err_vma_unpin;
@@ -2165,7 +2167,7 @@ static int gen8_modify_context(struct intel_context *ce,
lockdep_assert_held(&ce->pin_mutex);
- rq = i915_request_create(ce->engine->kernel_context);
+ rq = intel_engine_create_kernel_request(ce->engine);
if (IS_ERR(rq))
return PTR_ERR(rq);