Re: [PATCH i-g-t] tests/kms_pipe_crc_basic: Reset GPU before running subtests

[Mika Kahola <mika.kahola@intel.com>]

On Tue, 2017-06-06 at 15:27 +0300, Ville Syrjälä wrote:
> On Tue, Jun 06, 2017 at 03:20:46PM +0300, Mika Kahola wrote:
> > 
> > It has been noticed by our CI BAT testing that in some 1%-3%
> > probability
> > kms_pipe_crc_basic subtest read-crc-pipe-x-frame-sequence fails
> > when
> > comparing gathered CRC frames. However, running kms_pipe_crc_basic
> > subtests alone i.e. outside BAT I was unable to replicate the
> > issue.
> > 
> > The patch proposes a GPU reset before running the subtests. This
> > way we
> > can ensure that GPU register settings are reinitialized if they
> > have been
> > altered by the tests executed earlier in BAT.
> What does GPU reset have to do with display CRCs?
It's unclear but when you do it I was unable to replicate this in
couple hundred BAT runs. Maybe the error probability just hits below 1%
mark with this.

> 
> > 
> > 
> > The issue has been seen on following bug reports
> > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=99788
> > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=100367
> > 
> > Signed-off-by: Mika Kahola <mika.kahola@intel.com>
> > ---
> >  tests/kms_pipe_crc_basic.c | 10 ++++++++++
> >  1 file changed, 10 insertions(+)
> > 
> > diff --git a/tests/kms_pipe_crc_basic.c
> > b/tests/kms_pipe_crc_basic.c
> > index f49b434..e1940e6 100644
> > --- a/tests/kms_pipe_crc_basic.c
> > +++ b/tests/kms_pipe_crc_basic.c
> > @@ -175,6 +175,13 @@ static void test_read_crc(data_t *data, int
> > pipe, unsigned flags)
> >  	igt_require_f(valid_connectors, "No connector found for
> > pipe %i\n", pipe);
> >  }
> >  
> > +static void reset_gpu(void)
> > +{
> > +	int fd = drm_open_driver(DRIVER_INTEL);
> > +	igt_post_hang_ring(fd, igt_hang_ring(fd,
> > I915_EXEC_DEFAULT));
> > +	close(fd);
> > +}
> > +
> >  data_t data = {0, };
> >  
> >  igt_main
> > @@ -194,6 +201,9 @@ igt_main
> >  		data.debugfs = igt_debugfs_dir(data.drm_fd);
> >  	}
> >  
> > +	/* before running tests, reset gpu */
> > +	reset_gpu();
> > +
> >  	igt_subtest("bad-pipe")
> >  		test_bad_command(&data, "pipe D none");
> >  
> > -- 
> > 2.7.4
> > 
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx@lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
-- 
Mika Kahola - Intel OTC

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