[Intel-gfx] [PATCH i-g-t v3] tests/kms_flip: Adjust tolerance when counting frames

[Chris Wilson]

On Fri, May 13, 2016 at 01:00:33PM +0100, Chris Wilson wrote:
> On Fri, May 13, 2016 at 02:45:09PM +0300, Gabriel Feceoru wrote:
> > basic-flip-vs-wf_vblank subtest sometimes fails asserting counted frames to
> > be aproximately equal with the estimated number.
> > 
> > This is a false negative, one of the reasons being the precision lost when
> > truncating a fractional number.
> > 
> > Fixed this by using floating point arithmetic.
> > 
> > Cc: Jani Nikula <jani.nikula at intel.com>
> > Cc: Daniel Vetter <daniel.vetter at intel.com>
> > Signed-off-by: Gabriel Feceoru <gabriel.feceoru at intel.com>
> > ---
> >  tests/kms_flip.c | 8 ++++----
> >  1 file changed, 4 insertions(+), 4 deletions(-)
> > 
> > diff --git a/tests/kms_flip.c b/tests/kms_flip.c
> > index eda2fcc..6ec97d0 100644
> > --- a/tests/kms_flip.c
> > +++ b/tests/kms_flip.c
> > @@ -1182,13 +1182,13 @@ static void check_final_state(struct test_output *o, struct event_state *es,
> >  	/* Verify we drop no frames, but only if it's not a TV encoder, since
> >  	 * those use some funny fake timings behind userspace's back. */
> >  	if (o->flags & TEST_CHECK_TS && !analog_tv_connector(o)) {
> > -		int expected;
> > +		double expected;
> >  		int count = es->count;
> >  
> >  		count *= o->seq_step;
> > -		expected = elapsed / frame_time(o);
> 
> int expected = count * frame_time(o);
> igt_assert_f(100 * expected >= elasped * 99 && 100 * count <= expected * 101,

igt_assert_f(100 * expected >= elasped * 99 && 100 * expected <= elasped * 101,
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre