drm/i915/selftests: Flush the preemption request before waiting

Make sure that the request has been submitted to HW before we begin our
wait. This reduces our reliance on the semaphore yield interrupt driving
the preemption request.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201222113536.3775-2-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/gt/selftest_lrc.c b/drivers/gpu/drm/i915/gt/selftest_lrc.c
index 6f21cdfd09039b41bf992461b947a159e65e6a3d..6b069bb1ddcc50547e7d964fbaabc89a7cf7c69e 100644 (file)
--- a/drivers/gpu/drm/i915/gt/selftest_lrc.c
+++ b/drivers/gpu/drm/i915/gt/selftest_lrc.c
@@ -607,6 +607,10 @@ static int __live_lrc_gpr(struct intel_engine_cs *engine,
                err = emit_semaphore_signal(engine->kernel_context, slot);
                if (err)
                        goto err_rq;
+
+               err = wait_for_submit(engine, rq, HZ / 2);
+               if (err)
+                       goto err_rq;
        } else {
                slot[0] = 1;
                wmb();