[igt-dev] [PATCH i-g-t] tests/i915_pm_freq_api: Add a suspend subtest

[Belgaumkar, Vinay]

On 6/7/2023 2:12 PM, Dixit, Ashutosh wrote:
> On Tue, 06 Jun 2023 13:35:35 -0700, Vinay Belgaumkar wrote:
> Hi Vinay,
>
>> Verify that SLPC API works as expected after a suspend.
>>
>> Signed-off-by: Vinay Belgaumkar <vinay.belgaumkar at intel.com>
>> ---
>>   tests/i915/i915_pm_freq_api.c | 30 ++++++++++++++++++++++++++++++
>>   1 file changed, 30 insertions(+)
>>
>> diff --git a/tests/i915/i915_pm_freq_api.c b/tests/i915/i915_pm_freq_api.c
>> index 9005cd220..f35f1f8e0 100644
>> --- a/tests/i915/i915_pm_freq_api.c
>> +++ b/tests/i915/i915_pm_freq_api.c
>> @@ -18,6 +18,9 @@
>>    *
>>    * SUBTEST: freq-reset
>>    * Description: Test basic freq API works after a reset
>> + *
>> + * SUBTEST: freq-suspend
>> + * Description: Test basic freq API works after a runtime suspend
>>    */
>>
>>   IGT_TEST_DESCRIPTION("Test SLPC freq API");
>> @@ -99,6 +102,24 @@ static void test_reset(int i915, int dirfd, int gt)
>> 	igt_assert(get_freq(dirfd, RPS_MAX_FREQ_MHZ) == rpn);
>>   }
>>
>> +static void test_suspend(int i915, int dirfd, int gt)
>> +{
>> +	uint32_t rpn = get_freq(dirfd, RPS_RPn_FREQ_MHZ);
>> +
>> +	igt_assert(set_freq(dirfd, RPS_MIN_FREQ_MHZ, rpn) > 0);
>> +	igt_assert(set_freq(dirfd, RPS_MAX_FREQ_MHZ, rpn) > 0);
>> +	usleep(ACT_FREQ_LATENCY_US);
>> +	igt_assert(get_freq(dirfd, RPS_MIN_FREQ_MHZ) == rpn);
>> +	igt_assert(get_freq(dirfd, RPS_MAX_FREQ_MHZ) == rpn);
>> +
>> +	/* Manually trigger a suspend */
>> +	igt_system_suspend_autoresume(SUSPEND_STATE_S3,
>> +				      SUSPEND_TEST_NONE);
>> +
>> +	igt_assert(get_freq(dirfd, RPS_MIN_FREQ_MHZ) == rpn);
>> +	igt_assert(get_freq(dirfd, RPS_MAX_FREQ_MHZ) == rpn);
> I am wondering what the purpose/value of this test (and also "freq-reset")
> is?  How can the "set" min/max set freq (which are just input settings)
> change whether or not there is a suspend/resume or a reset? Especially when
> we just return cached min/max values from i915?

It is mainly checking that we don't smother the softlimit during a reset 
or suspend flow. In addition, it also tests the read/write interface 
works as expected after those events.

Thanks,

Vinay.

>
> Thanks.
> --
> Ashutosh
>
>
>> +}
>> +
>>   igt_main
>>   {
>> 	int i915 = -1;
>> @@ -143,6 +164,15 @@ igt_main
>> 				test_reset(i915, dirfd, gt);
>> 	}
>>
>> +	igt_describe("Test basic freq API works after suspend");
>> +	igt_subtest_with_dynamic_f("freq-suspend") {
>> +		int dirfd, gt;
>> +
>> +		for_each_sysfs_gt_dirfd(i915, dirfd, gt)
>> +			igt_dynamic_f("gt%u", gt)
>> +				test_suspend(i915, dirfd, gt);
>> +	}
>> +
>> 	igt_fixture {
>> 		int dirfd, gt;
>> 		/* Restore frequencies */
>> --
>> 2.38.1
>>