[PATCH 5.4 07/18] drm/amd/display: Fix for the no Audio bug with Tiled Displays

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

From: Mustapha Ghaddar <mghaddar@amd.com>

[ Upstream commit 5ceaebcda9061c04f439c93961f0819878365c0f ]

[WHY]
It seems like after a series of plug/unplugs we end up in a situation
where tiled display doesnt support Audio.

[HOW]
The issue seems to be related to when we check streams changed after an
HPD, we should be checking the audio_struct as well to see if any of its
values changed.

Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Mustapha Ghaddar <mustapha.ghaddar@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/amd/display/dc/core/dc_resource.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
index f25ac17f47fa9..95a5310e9e661 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
@@ -1546,6 +1546,10 @@ bool dc_is_stream_unchanged(
 	if (old_stream->ignore_msa_timing_param != stream->ignore_msa_timing_param)
 		return false;
 
+	// Only Have Audio left to check whether it is same or not. This is a corner case for Tiled sinks
+	if (old_stream->audio_info.mode_count != stream->audio_info.mode_count)
+		return false;
+
 	return true;
 }
 
-- 
2.33.0