Re: [igt-dev] [PATCH i-g-t v2] tests/xe: Verify actual frequency on the basis of GT state

["Nilawar, Badal" <badal.nilawar@intel.com>]

On 18-07-2023 10:21, Dixit, Ashutosh wrote:
> On Mon, 17 Jul 2023 21:42:14 -0700, Dixit, Ashutosh wrote:
>>
>> On Mon, 17 Jul 2023 21:27:02 -0700, Nilawar, Badal wrote:
>>>
>>>>> @@ -226,6 +226,9 @@ static void test_freq_fixed(int fd, int gt_id)
>>>>>
>>>>> 	igt_debug("Starting testing fixed request\n");
>>>>>
>>>>> +	if (gt_idle)
>>>>> +		igt_require(igt_wait(xe_is_gt_in_c6(fd, gt_id), 1000, 1));
>>>>> +
>>>>> 	/*
>>>>> 	 * For Fixed freq we need to set both min and max to the desired value
>>>>> 	 * Then we check if hardware is actually operating at the desired freq
>>>>> @@ -235,13 +238,25 @@ static void test_freq_fixed(int fd, int gt_id)
>>>>> 	igt_assert(set_freq(fd, gt_id, "max", rpn) > 0);
>>>>> 	usleep(ACT_FREQ_LATENCY_US);
>>>>> 	igt_assert(get_freq(fd, gt_id, "cur") == rpn);
>>>>> -	igt_assert(get_freq(fd, gt_id, "act") == rpn);
>>>>> +
>>>>> +	if (gt_idle) {
>>>>> +		usleep(ACT_FREQ_LATENCY_US);
>>>>
>>>> Looks like this usleep should in the else? Since we've already igt_wait'ed
>>>> above for the idle case? In all places in this patch.
>>>
>>> As get_freq(fd, gt_id, "cur") will forcewake the gt so added usleep to gt
>>> to settle down.
>>
>> Ah good point. I missed that reading requested freq takes forcewake (unlike
>> act freq).
> 
> One idea to remove this extra delay would be to read act freq first and
> then read cur. Otherwise, maybe add a comment in one place saying reading
> cur will take forcewake. Thanks.
Flow wise cur should read first as it tells guc honored the request. I 
will add comment.

Regards,
Badal