[PATCH i-g-t v2] tests/intel/gem_exec_schedule: Update for MTL RCS/CCS w/a

[Kamil Konieczny]

Hi John.C.Harrison,
On 2024-01-10 at 12:44:58 -0800, John.C.Harrison at Intel.com wrote:
> From: johnharr <johnharr at invalid-email.com>
-------------------------- ^^^^^^^^^^^^^^^^^
Looks like an error, checkpatch.pl complains about this.
imho it should be:

From: John Harrison <John.C.Harrison at Intel.com>

> 
> The RCS/CCS w/a means that if spinners are sent to both RCS and CCS
> engines then the system is dead and requires a reset. Even
> pre-emptible spinners cannot be pre-empted due to the nature of the
> w/a. So, do not get into that situation.
> 
> v2: Expand code comment (review feedback by Ashutosh)
> 
> Signed-off-by: John Harrison <John.C.Harrison at Intel.com>
> Reviewed-by: Ashutosh Dixit <ashutosh.dixit at intel.com>
> ---
>  tests/intel/gem_exec_schedule.c | 22 ++++++++++++++++++++++
>  1 file changed, 22 insertions(+)
> 
> diff --git a/tests/intel/gem_exec_schedule.c b/tests/intel/gem_exec_schedule.c
> index 183ee1a214bb..61b1a32332b4 100644
> --- a/tests/intel/gem_exec_schedule.c
> +++ b/tests/intel/gem_exec_schedule.c
> @@ -443,6 +443,22 @@
>  
>  IGT_TEST_DESCRIPTION("Check that we can control the order of execution");
>  
> +/*
> + * The RCS/CCS workaround on MTL means that if spinners are sent to both RCS
> + * and CCS engines concurrently then the system is effectively dead and will
> + * require a reset of both engines to recover. Even pre-emptible spinners
> + * cannot be pre-empted due to the nature of the w/a. The requests must run
> + * to completion or be reset. And in the case of certain IGT tests, there is
> + * no completion until after the pre-emption. The result being that the tests
> + * get killed by the heartbeat and fail.
> + *
> + * So, avoid that situation when running those tests on MTL by skipping the
> + * compute engines.
> + */
> +static bool skip_bad_engine(int fd, const struct intel_execution_engine2 *e) {
--------------------------------------------------------------------------------^

Please put '{' in separate line (see offset_in_page() below).

Regards,
Kamil

> +	return IS_METEORLAKE(intel_get_drm_devid(fd)) && (e->class == I915_ENGINE_CLASS_COMPUTE);
> +}
> +
>  static unsigned int offset_in_page(void *addr)
>  {
>  	return (uintptr_t)addr & 4095;
> @@ -2006,6 +2022,9 @@ static igt_spin_t *__noise(int fd, uint64_t ahnd, const intel_ctx_t *ctx,
>  	gem_context_set_priority(fd, ctx->id, prio);
>  
>  	for_each_ctx_engine(fd, ctx, e) {
> +		if (skip_bad_engine(fd, e))
> +			continue;
> +
>  		if (spin == NULL) {
>  			spin = __igt_spin_new(fd,
>  					      .ahnd = ahnd,
> @@ -2313,6 +2332,9 @@ static void preempt_self(int fd, const intel_ctx_cfg_t *cfg,
>  	n = 0;
>  	gem_context_set_priority(fd, ctx[HI]->id, MIN_PRIO);
>  	for_each_ctx_cfg_engine(fd, cfg, e) {
> +		if (skip_bad_engine(fd, e))
> +			continue;
> +
>  		spin[n] = __igt_spin_new(fd,
>  					 .ahnd = ahnd[NOISE],
>  					 .ctx = ctx[NOISE],
> -- 
> 2.43.0
>