[igt-dev] [PATCH i-g-t] tests/kms_chamelium: reduce flatline test amplitude

[Simon Ser]

Set flatline test amplitude to 0.1 instead of 0.9. There have been concerns
about edge-cases where bad TV hardware is connected via HDMI/DP and breaks when
a DC offset is sent.

This is a first mitigation. A second mitigation to only send audio to the
Chamelium device instead of all HDMI/DP ports is planned, but requires changes
in ALSA and/or DRM.

Signed-off-by: Simon Ser <simon.ser at intel.com>
---
 tests/kms_chamelium.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/kms_chamelium.c b/tests/kms_chamelium.c
index 36e92e975d64..0bfb0838d013 100644
--- a/tests/kms_chamelium.c
+++ b/tests/kms_chamelium.c
@@ -775,7 +775,7 @@ test_display_frame_dump(data_t *data, struct chamelium_port *port)
 /* A streak of 3 gives confidence that the signal is good. */
 #define MIN_STREAK 3

-#define FLATLINE_AMPLITUDE 0.9 /* normalized, ie. in [0, 1] */
+#define FLATLINE_AMPLITUDE 0.1 /* normalized, ie. in [0, 1] */
 #define FLATLINE_AMPLITUDE_ACCURACY 0.001 /* ± 0.1 % of the full amplitude */
 #define FLATLINE_ALIGN_ACCURACY 0 /* number of samples */

--
2.22.0