[Intel-gfx] [PATCH v4 1/3] drm/i915: fix whitelist selftests with readonly registers

[Lionel Landwerlin]

When a register is readonly there is not much we can tell about its
value (apart from its default value?). This can be covered by tests
exercising the value of the register from userspace.

For PS_INVOCATION_COUNT we've got the following piglit tests :

   KHR-GL45.pipeline_statistics_query_tests_ARB.functional_fragment_shader_invocations

Vulkan CTS tests :

   dEQP-VK.query_pool.statistics_query.fragment_shader_invocations.*

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin at intel.com>
---
 drivers/gpu/drm/i915/gt/selftest_workarounds.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/i915/gt/selftest_workarounds.c b/drivers/gpu/drm/i915/gt/selftest_workarounds.c
index f12cb20fe785..801a94516bae 100644
--- a/drivers/gpu/drm/i915/gt/selftest_workarounds.c
+++ b/drivers/gpu/drm/i915/gt/selftest_workarounds.c
@@ -926,6 +926,9 @@ check_whitelisted_registers(struct intel_engine_cs *engine,
 
 	err = 0;
 	for (i = 0; i < engine->whitelist.count; i++) {
+		if (engine->whitelist.list[i].reg & RING_FORCE_TO_NONPRIV_RD)
+			continue;
+
 		if (!fn(engine, a[i], b[i], engine->whitelist.list[i].reg))
 			err = -EINVAL;
 	}
-- 
2.21.0.392.gf8f6787159e