[igt-dev] [PATCH i-g-t 68/77] igt/dummyload: Require an intel_ctx_t for POLL_RUN and !ALL_ENGINES

[Dixit, Ashutosh]

On Mon, 14 Jun 2021 09:38:53 -0700, Jason Ekstrand wrote:
>
> diff --git a/lib/igt_dummyload.c b/lib/igt_dummyload.c
> index b0a7b361c..25e49de47 100644
> --- a/lib/igt_dummyload.c
> +++ b/lib/igt_dummyload.c
> @@ -421,22 +421,12 @@ igt_spin_factory(int fd, const struct igt_spin_factory *opts)
>  {
>	igt_spin_t *spin;
>
> -	if (opts->engine != ALL_ENGINES) {
> -		struct intel_execution_engine2 e;
> -		int class;
> -
> -		if (opts->ctx) {
> -			class = opts->ctx->cfg.engines[opts->engine].engine_class;
> -		} else if (!gem_context_lookup_engine(fd, opts->engine,
> -						      opts->ctx_id, &e)) {
> -			class = e.class;
> -		} else {
> -			gem_require_ring(fd, opts->engine);
> -			class = gem_execbuf_flags_to_engine_class(opts->engine);
> -		}
> +	if ((opts->flags & IGT_SPIN_POLL_RUN) && opts->engine != ALL_ENGINES) {
> +		unsigned int class;
>
> -		if (opts->flags & IGT_SPIN_POLL_RUN)
> -			igt_require(gem_class_can_store_dword(fd, class));
> +		igt_assert(opts->ctx);
> +		class = intel_ctx_engine_class(opts->ctx, opts->engine);
> +		igt_require(gem_class_can_store_dword(fd, class));
>	}

I am not sure if this is correct. If I straightforwardly enforce opts->ctx
and tranform the original logic I get this:

        if (opts->engine != ALL_ENGINES) {
                int class;

                igt_assert(opts->ctx);
                class = intel_ctx_engine_class(opts->ctx, opts->engine);
                if (opts->flags & IGT_SPIN_POLL_RUN)
                        igt_require(gem_class_can_store_dword(fd, class));
        }

or even

        if (opts->engine != ALL_ENGINES) {
                igt_assert(opts->ctx);
                if (opts->flags & IGT_SPIN_POLL_RUN) {
	                int class = intel_ctx_engine_class(opts->ctx, opts->engine);
                        igt_require(gem_class_can_store_dword(fd, class));
		}
        }

Importantly, "igt_assert(opts->ctx)" is invoked independent of opts->flags,
unlike the code in the patch.