[Intel-gfx] [PATCH v7 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>
Fixes: 86554f48e511 ("drm/i915/selftests: Verify whitelist of context registers")
---
 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..a06f96df1bfd 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.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