[PATCH 07/31] drm/amd/display: Add explicit FIFO disable for DP blank

[Jasdeep Dhillon]

From: Nicholas Kazlauskas <nicholas.kazlauskas at amd.com>

[Why]
We rely on DMCUB to do this when disabling the link but it should
actually come before we disable the DP VID stream.

If we don't then the FIFO can end up with underflow that persists
the next time it's enabled.

[How]
Add a DCN314 specific blank sequence that will disable the DIG FIFO
first.

Reviewed-by: Syed Hassan <Syed.Hassan at amd.com>
Acked-by: Jasdeep Dhillon <jdhillon at amd.com>
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas at amd.com>
---
 .../display/dc/dcn314/dcn314_dio_stream_encoder.c    | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/dc/dcn314/dcn314_dio_stream_encoder.c b/drivers/gpu/drm/amd/display/dc/dcn314/dcn314_dio_stream_encoder.c
index 914c5da737ed..eeee3107bd57 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn314/dcn314_dio_stream_encoder.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn314/dcn314_dio_stream_encoder.c
@@ -261,6 +261,16 @@ static bool is_two_pixels_per_containter(const struct dc_crtc_timing *timing)
 	return two_pix;
 }
 
+void enc314_stream_encoder_dp_blank(
+	struct dc_link *link,
+	struct stream_encoder *enc)
+{
+	/* New to DCN314 - disable the FIFO before VID stream disable. */
+	enc314_disable_fifo(enc);
+
+	enc1_stream_encoder_dp_blank(link, enc);
+}
+
 static void enc314_stream_encoder_dp_unblank(
 		struct dc_link *link,
 		struct stream_encoder *enc,
@@ -408,7 +418,7 @@ static const struct stream_encoder_funcs dcn314_str_enc_funcs = {
 	.stop_dp_info_packets =
 		enc1_stream_encoder_stop_dp_info_packets,
 	.dp_blank =
-		enc1_stream_encoder_dp_blank,
+		enc314_stream_encoder_dp_blank,
 	.dp_unblank =
 		enc314_stream_encoder_dp_unblank,
 	.audio_mute_control = enc3_audio_mute_control,
-- 
2.25.1