Re: [PATCH i-g-t] tests/kms_setmode: Relax vblank timing tolerance from 1 scanline to 1%

["Jason-JH Lin (林睿祥)" <Jason-JH.Lin@mediatek.com>]

[snip]

> >  	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",
> > +		igt_warn("vblank interval differs from modeline!
> > expected
> > %.1fus, "
> > +			 "measured %1.fus +- %.3fus, difference
> > %.1fus (%.1f
> > sigma, %.1f scanlines) - "
> > +			 "strict check failed but continuing with
> > relaxed
> > validation\n",
> >  			  expected, mean, stddev,
> >  			  fabs(mean - expected),
> >  			  fabs(mean - expected) / stddev,
> >  			  fabs(mean - expected) /
> > line_time(kmode));
> > +	}
> > +
> imho, we can first try the strict checks, and if they fail, fall back
> to relaxed validation. Another approach could be as shown below.
> bool strict_failed = false;
> 
> /* Strict checks */
> if (accuracy >= line_time(kmode)) {
>     igt_warn(...);
>     strict_failed = true;
> }
> 
> if (fabs(mean - expected) >= max(line_time(kmode), 1.718 * stddev)) {
>     igt_warn(...);
>     strict_failed = true;
> }
> 
> /* Relaxed validation */
> if (strict_failed)
>     igt_info("Passed relaxed validation (strict failed)\n");
> else
>     igt_info("Passed strict validation\n");
> 
> return true;
> 

Thanks for the good idea!
I'll send V2 as your suggestion.

Regards,
Jason-JH Lin