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

[Lionel Landwerlin]

Ship it!

On 29/06/2019 16:13, Chris Wilson wrote:
> From: Lionel Landwerlin <lionel.g.landwerlin at intel.com>
>
> 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.*
>
> v2: Use a local to shrink under 80cols.
>
> Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin at intel.com>
> Fixes: 86554f48e511 ("drm/i915/selftests: Verify whitelist of context registers")
> Tested-by: Anuj Phogat <anuj.phogat at gmail.com>
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> ---
> Fixes is a bit much, since the test is still very much nerfed and not
> complemented by a test for read-only non-priv registers...
> -Chris
> ---
>   drivers/gpu/drm/i915/gt/selftest_workarounds.c | 7 ++++++-
>   1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/gt/selftest_workarounds.c b/drivers/gpu/drm/i915/gt/selftest_workarounds.c
> index f12cb20fe785..b933d831eeb1 100644
> --- a/drivers/gpu/drm/i915/gt/selftest_workarounds.c
> +++ b/drivers/gpu/drm/i915/gt/selftest_workarounds.c
> @@ -926,7 +926,12 @@ check_whitelisted_registers(struct intel_engine_cs *engine,
>   
>   	err = 0;
>   	for (i = 0; i < engine->whitelist.count; i++) {
> -		if (!fn(engine, a[i], b[i], engine->whitelist.list[i].reg))
> +		const struct i915_wa *wa = &engine->whitelist.list[i];
> +
> +		if (i915_mmio_reg_offset(wa->reg) & RING_FORCE_TO_NONPRIV_RD)
> +			continue;
> +
> +		if (!fn(engine, a[i], b[i], wa->reg))
>   			err = -EINVAL;
>   	}
>