Re: [igt-dev] [Intel-gfx] [PATCH i-g-t 1/2] lib: Add --skip-crc-compare option

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Fri, Feb 22, 2019 at 03:32:50PM +0100, Daniel Vetter wrote:
> On Wed, Feb 20, 2019 at 04:34:21PM -0800, Matt Roper wrote:
> > When using --interactive-debug, it's sometimes desirable to ignore CRC
> > mismatches and let the test proceed as if they passed so that the
> > on-screen outcome can be inspected.  Let's add a debug option to allow
> > this.
> > 
> > Cc: igt-dev@lists.freedesktop.org
> > Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
> > ---
> >  lib/igt_core.c    | 7 +++++++
> >  lib/igt_core.h    | 1 +
> >  lib/igt_debugfs.c | 8 +++++++-
> >  3 files changed, 15 insertions(+), 1 deletion(-)
> > 
> > diff --git a/lib/igt_core.c b/lib/igt_core.c
> > index 71b05d3b..5523950f 100644
> > --- a/lib/igt_core.c
> > +++ b/lib/igt_core.c
> > @@ -256,6 +256,7 @@
> >  
> >  static unsigned int exit_handler_count;
> >  const char *igt_interactive_debug;
> > +bool igt_skip_crc_compare;
> >  
> >  /* subtests helpers */
> >  static bool list_subtests = false;
> > @@ -285,6 +286,7 @@ enum {
> >   OPT_DESCRIPTION,
> >   OPT_DEBUG,
> >   OPT_INTERACTIVE_DEBUG,
> > + OPT_SKIP_CRC,
> >   OPT_HELP = 'h'
> >  };
> >  
> > @@ -552,6 +554,7 @@ static void print_usage(const char *help_str, bool output_on_stderr)
> >  		   "  --run-subtest <pattern>\n"
> >  		   "  --debug[=log-domain]\n"
> >  		   "  --interactive-debug[=domain]\n"
> > +		   "  --skip-crc-compare\n"
> >  		   "  --help-description\n"
> >  		   "  --help\n");
> >  	if (help_str)
> > @@ -668,6 +671,7 @@ static int common_init(int *argc, char **argv,
> >  		{"help-description", 0, 0, OPT_DESCRIPTION},
> >  		{"debug", optional_argument, 0, OPT_DEBUG},
> >  		{"interactive-debug", optional_argument, 0, OPT_INTERACTIVE_DEBUG},
> > +		{"skip-crc-compare", 0, 0, OPT_SKIP_CRC},
> >  		{"help", 0, 0, OPT_HELP},
> >  		{0, 0, 0, 0}
> >  	};
> > @@ -768,6 +772,9 @@ static int common_init(int *argc, char **argv,
> >  			print_test_description();
> >  			ret = -1;
> >  			goto out;
> > +		case OPT_SKIP_CRC:
> > +			igt_skip_crc_compare = true;
> > +			goto out;
> >  		case OPT_HELP:
> >  			print_usage(help_str, false);
> >  			ret = -1;
> > diff --git a/lib/igt_core.h b/lib/igt_core.h
> > index 47ffd9e7..f12fc5cb 100644
> > --- a/lib/igt_core.h
> > +++ b/lib/igt_core.h
> > @@ -843,6 +843,7 @@ bool igt_run_in_simulation(void);
> >  void igt_skip_on_simulation(void);
> >  
> >  extern const char *igt_interactive_debug;
> > +extern bool igt_skip_crc_compare;
> >  
> >  /**
> >   * igt_log_level:
> > diff --git a/lib/igt_debugfs.c b/lib/igt_debugfs.c
> > index 640c78e9..04d1648b 100644
> > --- a/lib/igt_debugfs.c
> > +++ b/lib/igt_debugfs.c
> > @@ -405,6 +405,12 @@ static bool igt_find_crc_mismatch(const igt_crc_t *a, const igt_crc_t *b,
> >   * assert that CRCs match, never that they are different. Otherwise there might
> >   * be random testcase failures when different screen contents end up with the
> >   * same CRC by chance.
> > + *
> > + * Passing --skip-crc-compare on the command line will force this function
> > + * to always pass, which can be useful in interactive debugging where you
> > + * might know the test will fail, but still want the test to keep going as if
> > + * it had succeeded so that you can see the on-screen behavior.
> > + *
> >   */
> >  void igt_assert_crc_equal(const igt_crc_t *a, const igt_crc_t *b)
> >  {
> > @@ -416,7 +422,7 @@ void igt_assert_crc_equal(const igt_crc_t *a, const igt_crc_t *b)
> >  		igt_debug("CRC mismatch at index %d: 0x%x != 0x%x\n", index,
> >  			  a->crc[index], b->crc[index]);
> >  
> > -	igt_assert(!mismatch);
> > +	igt_assert(!mismatch || igt_skip_crc_compare);
> 
> I think an igt_debug line here could be useful when we skip the assert.
> With that

Daniel, is the debug print just above not sufficient? Or would you like
a more explicit indication that we skipped the assert even though there
was mismatch?

I guess we could do something like:

if (mismatch)
 igt_debug("CRC mismatch%s at index %d: 0x%x != 0x%x\n",
           skip_crc_compare ? " (ignored)" : "",
	   index, a->crc[index], b->crc[index]);

to avoid spamming the log with two lines per mismatch?

I was just looking for this knob until I realized we never applied this
patch :/

> 
> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> 
> aka Ville convinced me.
> -Daniel
> 
> >  }
> >  
> >  /**
> > -- 
> > 2.14.5
> > 
> > _______________________________________________
> > igt-dev mailing list
> > igt-dev@lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/igt-dev
> 
> -- 
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Ville Syrjälä
Intel
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