[igt-dev] [PATCH i-g-t v2] tests/kms_setmode: degrade assert to debug

[Rodrigo Siqueira Jordao]

+Mark

On 2022-09-15 12:06, Hamza Mahfooz wrote:
> [Adding Petri and Siqueira]
> 
> On 2022-09-13 11:08, Hamza Mahfooz wrote:
>> Unfortunately, there are too many sources of jitter that can cause the
>> vblank interval approximation obtained from DRM_IOCTL_WAIT_VBLANK to be
>> off by more than a scanline for this assert to be useful. So, to allow
>> this test to pass consistently degrade the assert to a debug.
>>
>> Signed-off-by: Hamza Mahfooz <hamza.mahfooz at amd.com>
>> ---
>> v2: fix logic
>> ---
>>   tests/kms_setmode.c | 12 ++++++------
>>   1 file changed, 6 insertions(+), 6 deletions(-)
>>
>> diff --git a/tests/kms_setmode.c b/tests/kms_setmode.c
>> index bfa10891..58abfe14 100644
>> --- a/tests/kms_setmode.c
>> +++ b/tests/kms_setmode.c
>> @@ -527,12 +527,12 @@ static void check_timings(int crtc_idx, const 
>> drmModeModeInfo *kmode)
>>        * See:
>>        * 
>> https://en.wikipedia.org/wiki/Standard_deviation#Rules_for_normally_distributed_data
>>        */
>> -    igt_assert_f(fabs(mean - expected) < max(line_time(kmode), 1.718 
>> * stddev),
>> -             "vblank interval differs from modeline! expected %.1fus, 
>> measured %1.fus +- %.3fus, difference %.1fus (%.1f sigma, %.1f 
>> scanlines)\n",
>> -             expected, mean, stddev,
>> -             fabs(mean - expected),
>> -             fabs(mean - expected) / stddev,
>> -             fabs(mean - expected) / line_time(kmode));
>> +    if (fabs(mean - expected) > max(line_time(kmode), 1.718 * stddev))
>> +        igt_info("vblank interval differs from modeline! expected 
>> %.1fus, measured %1.fus +- %.3fus, difference %.1fus (%.1f sigma, %.1f 
>> scanlines)\n",
>> +             expected, mean, stddev,
>> +             fabs(mean - expected),
>> +             fabs(mean - expected) / stddev,
>> +             fabs(mean - expected) / line_time(kmode));
>>   }
>>   static void test_crtc_config(const struct test_config *tconf,
>