[igt-dev] [PATCH i-g-t 1/4] i915/perf_pmu: Verify RC6 measurements before/after suspend

[Tvrtko Ursulin]

On 14/12/2020 10:51, Chris Wilson wrote:
> RC6 should work before suspend, and continue to increment while idle
> after suspend. Should.
> 
> v2: Include a longer sleep after suspend; it appears we are reticent to
> idle so soon after waking up.
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> ---
>   tests/i915/perf_pmu.c | 28 +++++++++++++++++++++++++---
>   1 file changed, 25 insertions(+), 3 deletions(-)
> 
> diff --git a/tests/i915/perf_pmu.c b/tests/i915/perf_pmu.c
> index cb7273142..0b470c1bc 100644
> --- a/tests/i915/perf_pmu.c
> +++ b/tests/i915/perf_pmu.c
> @@ -170,6 +170,7 @@ static unsigned int measured_usleep(unsigned int usec)
>   #define TEST_RUNTIME_PM (8)
>   #define FLAG_LONG (16)
>   #define FLAG_HANG (32)
> +#define TEST_S3 (64)
>   
>   static igt_spin_t * __spin_poll(int fd, uint32_t ctx,
>   				const struct intel_execution_engine2 *e)
> @@ -1578,7 +1579,7 @@ test_frequency_idle(int gem_fd)
>   		     "Actual frequency should be 0 while parked!\n");
>   }
>   
> -static bool wait_for_rc6(int fd)
> +static bool wait_for_rc6(int fd, int timeout)
>   {
>   	struct timespec tv = {};
>   	uint64_t start, now;
> @@ -1594,7 +1595,7 @@ static bool wait_for_rc6(int fd)
>   		now = pmu_read_single(fd);
>   		if (now - start > 1e6)
>   			return true;
> -	} while (!igt_seconds_elapsed(&tv));
> +	} while (igt_seconds_elapsed(&tv) <= timeout);
>   
>   	return false;
>   }
> @@ -1636,14 +1637,32 @@ test_rc6(int gem_fd, unsigned int flags)
>   		}
>   	}
>   
> -	igt_require(wait_for_rc6(fd));
> +	igt_require(wait_for_rc6(fd, 1));
>   
>   	/* While idle check full RC6. */
>   	prev = __pmu_read_single(fd, &ts[0]);
>   	slept = measured_usleep(duration_ns / 1000);
>   	idle = __pmu_read_single(fd, &ts[1]);
> +
>   	igt_debug("slept=%lu perf=%"PRIu64"\n", slept, ts[1] - ts[0]);
> +	assert_within_epsilon(idle - prev, ts[1] - ts[0], tolerance);
> +
> +	if (flags & TEST_S3) {
> +		prev = __pmu_read_single(fd, &ts[0]);
> +		igt_system_suspend_autoresume(SUSPEND_STATE_MEM,
> +					      SUSPEND_TEST_NONE);
> +		idle = __pmu_read_single(fd, &ts[1]);
> +		igt_debug("suspend=%"PRIu64"\n", ts[1] - ts[0]);
> +		//assert_within_epsilon(idle - prev, ts[1] - ts[0], tolerance);
> +	}
> +
> +	igt_assert(wait_for_rc6(fd, 5));
>   
> +	prev = __pmu_read_single(fd, &ts[0]);
> +	slept = measured_usleep(duration_ns / 1000);
> +	idle = __pmu_read_single(fd, &ts[1]);
> +
> +	igt_debug("slept=%lu perf=%"PRIu64"\n", slept, ts[1] - ts[0]);

You plan to leave the C++ bit commented out above and just check it 
here? Doesn't seem it harms to check twice in the non-S3 case anyway, 
just asking.

Regards,

Tvrtko

>   	assert_within_epsilon(idle - prev, ts[1] - ts[0], tolerance);
>   
>   	/* Wake up device and check no RC6. */
> @@ -2245,6 +2264,9 @@ igt_main
>   	igt_subtest("rc6-runtime-pm-long")
>   		test_rc6(fd, TEST_RUNTIME_PM | FLAG_LONG);
>   
> +	igt_subtest("rc6-suspend")
> +		test_rc6(fd, TEST_S3);
> +
>   	/**
>   	 * Check render nodes are counted.
>   	 */
>