tests/kms_frontbuffer_tracking: Reduce fbc status spam, v2.

When FBC cannot be enabled in one of the tests, we get a lot of repeated
spam at DEBUG level, which overwrites any good debug level data that you
can hope to get out of the test.

When running at the debug level, output FBC info only if changed from last
time, so we don't get the repeated spam.

This makes the debug info from CI slightly more useful.

Changes since v1:
- Clear last_fbc_buf in fbc_wait_until_enabled.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
[mlankhorst: Remove stray from igt_core.c]
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>

1 files changed, 15 insertions, 1 deletions

diff --git a/tests/kms_frontbuffer_tracking.c b/tests/kms_frontbuffer_tracking.c
index 06b34ddb..2b85392d 100644
--- a/tests/kms_frontbuffer_tracking.c
+++ b/tests/kms_frontbuffer_tracking.c
@@ -755,12 +755,24 @@ static int __debugfs_write(const char *param, char *buf, int len)
 #define debugfs_read(p, arr) __debugfs_read(p, arr, sizeof(arr))
 #define debugfs_write(p, arr) __debugfs_write(p, arr, sizeof(arr))
 
+static char last_fbc_buf[128];
+
 static bool fbc_is_enabled(int lvl)
 {
 	char buf[128];
+	bool print = true;
 
 	debugfs_read("i915_fbc_status", buf);
-	igt_log(IGT_LOG_DOMAIN, lvl, "fbc_is_enabled()?\n%s", buf);
+	if (lvl != IGT_LOG_DEBUG)
+		last_fbc_buf[0] = '\0';
+	else if (strcmp(last_fbc_buf, buf))
+		strcpy(last_fbc_buf, buf);
+	else
+		print = false;
+
+	if (print)
+		igt_log(IGT_LOG_DOMAIN, lvl, "fbc_is_enabled()?\n%s", buf);
+
 	return strstr(buf, "FBC enabled\n");
 }
 
@@ -945,6 +957,8 @@ static bool fbc_stride_not_supported(void)
 
 static bool fbc_wait_until_enabled(void)
 {
+	last_fbc_buf[0] = '\0';
+
 	return igt_wait(fbc_is_enabled(IGT_LOG_DEBUG), 2000, 1);
 }