Re: [PATCH i-g-t] tests/kms_frontbuffer_tracking: increase FBC wait timeout to 5s

Lofstedt, Marta
2017-08-11T10:18:01Z

Paulo, my currently conclusion in https://bugs.freedesktop.org/show_bug.cgi?id=101623 is that the more than 2 second wait for enable_fbs only occurs when changing between draw domains, typically between blt and mmap_cpu.
To me this appear to be way too long time, but I am no expert here.
I don't think that the objective of this test is performance of domain changes, but if we have no other way to explore that issue, I guess we should not change the timeout.

/Marta

> -----Original Message-----
> From: Lofstedt, Marta
> Sent: Tuesday, August 8, 2017 2:15 PM
> To: Zanoni, Paulo R <paulo.r.zanoni@intel.com>; intel-
> gfx@lists.freedesktop.org
> Cc: Latvala, Petri <petri.latvala@intel.com>
> Subject: RE: [PATCH i-g-t] tests/kms_frontbuffer_tracking: increase FBC wait
> timeout to 5s
>
>
>
> > -----Original Message-----
> > From: Zanoni, Paulo R
> > Sent: Monday, August 7, 2017 5:54 PM
> > To: Lofstedt, Marta <marta.lofstedt@intel.com>; intel-
> > gfx@lists.freedesktop.org
> > Cc: Latvala, Petri <petri.latvala@intel.com>
> > Subject: Re: [PATCH i-g-t] tests/kms_frontbuffer_tracking: increase
> > FBC wait timeout to 5s
> >
> > Em Seg, 2017-08-07 às 06:51 +0000, Lofstedt, Marta escreveu:
> > > > -----Original Message-----
> > > > From: Zanoni, Paulo R
> > > > Sent: Friday, August 4, 2017 9:56 PM
> > > > To: Lofstedt, Marta <marta.lofstedt@intel.com>; intel-
> > > > gfx@lists.freedesktop.org
> > > > Cc: Latvala, Petri <petri.latvala@intel.com>
> > > > Subject: Re: [PATCH i-g-t] tests/kms_frontbuffer_tracking:
> > > > increase FBC wait timeout to 5s
> > > >
> > > > Em Sex, 2017-08-04 às 09:47 +0000, Lofstedt, Marta escreveu:
> > > > > +Paolo
> > > > >
> > > > > > -----Original Message-----
> > > > > > From: Lofstedt, Marta
> > > > > > Sent: Wednesday, June 28, 2017 2:17 PM
> > > > > > To: intel-gfx@lists.freedesktop.org
> > > > > > Cc: Latvala, Petri <petri.latvala@intel.com>; Lofstedt, Marta
> > > > > > <marta.lofstedt@intel.com>
> > > > > > Subject: [PATCH i-g-t] tests/kms_frontbuffer_tracking:
> > > > > > increase FBC wait timeout to 5s
> > > > > >
> > > > > > The subtests: igt@kms_frontbuffer_tracking@fbc-*draw*
> > > > > > has non-consistent results, pending between fail and pass.
> > > > > > The fails are always due to "FBC disabled".
> > > > > > With this increase in timeout the flip-flop behavior is no
> > > > > > longer reproducible.
> > > >
> > > > This is a partial revert of:
> > > >
> > > > 64590c7b768dc8d8dd962f812d5ff5a39e7e8b54
> > > >     kms_frontbuffer_tracking: reduce the FBC wait timeout to 2s
> > > >
> > > > (but there's no need to make it a full revert if you don't need)
> > > >
> > > > It would be nice to investigate why we're needing 5 seconds
> > > > instead of
> > > > 2 now, the document it in the commit message. Also document that
> > > > this is a partial revert.
> > >
> > > Paulo, do you have data backing up that 2 seconds was ever OK, I
> > > fail
> > > ~1/10 on various fbc subtests.
> >
> > All the data I have is the commit message of 64590c7b and the testing
> > I did. I would imagine something changed in the upstream tree since
> > then, causing this to need a longer timeout, that's why I suggested
> investigating.
> >
> If I run current IGT with Kernel 4.2.0, which was released 30 august 2015, that
> should be around the time when the 64590c7b was done, all
> kms_frontbuffer_tracking tests fail. If I reset IGT to 64590c7b half of the flip-
> flopping tests consistently fail the rest consistently pass over 10 runs. If I run
> IGT@64590c7b on 4.13-rc3+ all kms_fronbuffer_tracking fail. So, indeed
> some of these tests appear to actually have passed 2 years ago, but it also
> seem that both the tests and the i915 have change a lot during 2 years.
> Anyways, I will do some timing analyze to investigate what is really going on
> here.
>
> /Marta
>
> > >
> > > /Marta
> > > >
> > > > Acked-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
> > > >
> > >
> > > Thanks,
> > >
> > > > > >
> > > > > > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=101623
> > > > > > Signed-off-by: Marta Lofstedt <marta.lofstedt@intel.com>
> > > > > > ---
> > > > > >  tests/kms_frontbuffer_tracking.c | 2 +-
> > > > > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > > > >
> > > > > > diff --git a/tests/kms_frontbuffer_tracking.c
> > > > > > b/tests/kms_frontbuffer_tracking.c
> > > > > > index c24e4a81..8bec5d5a 100644
> > > > > > --- a/tests/kms_frontbuffer_tracking.c
> > > > > > +++ b/tests/kms_frontbuffer_tracking.c
> > > > > > @@ -923,7 +923,7 @@ static bool fbc_stride_not_supported(void)
> > > > > >
> > > > > >  static bool fbc_wait_until_enabled(void)  {
> > > > > > - return igt_wait(fbc_is_enabled(), 2000, 1);
> > > > > > + return igt_wait(fbc_is_enabled(), 5000, 1);
> > > > > >  }
> > > > > >
> > > > > >  static bool psr_wait_until_enabled(void)
> > > > > > --
> > > > > > 2.11.0
> > > > >
> > > > >