[PATCH 5.11 613/775] drm/amd/display: Remove Assert from dcn10_get_dig_frontend

[Greg Kroah-Hartman]

From: Eric Bernstein <eric.bernstein@xxxxxxx>

commit 83e6667b675f101fb66659dfa72e45d08773d763 upstream.

[Why]
In some cases, this function is called when DIG BE is not
connected to DIG FE, in which case a value of zero isn't
invalid and assert should not be hit.

[How]
Remove assert and handle ENGINE_ID_UNKNOWN result in calling
function.

Signed-off-by: Eric Bernstein <eric.bernstein@xxxxxxx>
Acked-by: Bindu Ramamurthy <bindu.r@xxxxxxx>
Tested-by: Daniel Wheeler <daniel.wheeler@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/gpu/drm/amd/display/dc/dcn10/dcn10_link_encoder.c |    1 -
 drivers/gpu/drm/amd/display/dc/dcn30/dcn30_hwseq.c        |    2 ++
 2 files changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_link_encoder.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_link_encoder.c
@@ -480,7 +480,6 @@ unsigned int dcn10_get_dig_frontend(stru
 		break;
 	default:
 		// invalid source select DIG
-		ASSERT(false);
 		result = ENGINE_ID_UNKNOWN;
 	}
 
--- a/drivers/gpu/drm/amd/display/dc/dcn30/dcn30_hwseq.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn30/dcn30_hwseq.c
@@ -539,6 +539,8 @@ void dcn30_init_hw(struct dc *dc)
 
 					fe = dc->links[i]->link_enc->funcs->get_dig_frontend(
 										dc->links[i]->link_enc);
+					if (fe == ENGINE_ID_UNKNOWN)
+						continue;
 
 					for (j = 0; j < dc->res_pool->stream_enc_count; j++) {
 						if (fe == dc->res_pool->stream_enc[j]->id) {