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

[Matt Roper]

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 at lists.freedesktop.org
Signed-off-by: Matt Roper <matthew.d.roper at 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);
 }
 
 /**
-- 
2.14.5