[PATCH 03/14] drm/amd/display: Only use analog stream encoder with analog engine

["Timur Kristóf" <timur.kristof@gmail.com>]

Some GPUs have analog connectors that work with a DP bridge chip
and don't actually have an internal DAC: Those should not use
the analog stream encoders.

Fixes: 5834c33fd3f6 ("drm/amd/display: Add concept of analog encoders (v2)")
Signed-off-by: Timur Kristóf <timur.kristof@gmail.com>
---
 .../gpu/drm/amd/display/dc/resource/dce100/dce100_resource.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/dc/resource/dce100/dce100_resource.c b/drivers/gpu/drm/amd/display/dc/resource/dce100/dce100_resource.c
index a916872db7bd..83b9abb64bfc 100644
--- a/drivers/gpu/drm/amd/display/dc/resource/dce100/dce100_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/resource/dce100/dce100_resource.c
@@ -979,7 +979,10 @@ struct stream_encoder *dce100_find_first_free_match_stream_enc_for_link(
 	struct dc_link *link = stream->link;
 	enum engine_id preferred_engine = link->link_enc->preferred_engine;
 
-	if (dc_is_rgb_signal(stream->signal))
+	/* Prefer analog engine if the link encoder has one.
+	 * Otherwise, it's an external encoder.
+	 */
+	if (dc_is_rgb_signal(stream->signal) && link->link_enc->analog_engine != ENGINE_ID_UNKNOWN)
 		preferred_engine = link->link_enc->analog_engine;
 
 	for (i = 0; i < pool->stream_enc_count; i++) {
-- 
2.52.0