drm/amd/display: Fix driver load crash in amdgpu_dm

[Why]
This fixes an regression introduced by:
    drm/amd/display: add stream ID and otg instance in dc_stream_state

During driver initialization, a null pointer deref is raised. This is
caused by searching for a stream status in the dc->current_state before
the dc_state swap happens at the end of dc_commit_state_no_check().
Since the swap has not happened, the dc_state to be swapped in should
be searched, and not dc->current_state.

[How]
Add a function that searches for the stream status within the given
dc_state, instead of dc->current_state. Use that before the state swap
happens in dc_commit_state_no_check().

Also remove duplicate occurrences of this function in amdgpu_dm.c.

Signed-off-by: Leo Li <sunpeng.li@amd.com>
Reviewed-by: Harry Wentland <Harry.Wentland@amd.com>
Acked-by: Nicholas Kazlauskas <Nicholas.Kazlauskas@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 27 insertions, 5 deletions

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_stream.c b/drivers/gpu/drm/amd/display/dc/core/dc_stream.c
index e498a9aa8035..996298c35f42 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_stream.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_stream.c
@@ -160,21 +160,43 @@ struct dc_stream_state *dc_create_stream_for_sink(
 	return stream;
 }
 
-struct dc_stream_status *dc_stream_get_status(
+/**
+ * dc_stream_get_status_from_state - Get stream status from given dc state
+ * @state: DC state to find the stream status in
+ * @stream: The stream to get the stream status for
+ *
+ * The given stream is expected to exist in the given dc state. Otherwise, NULL
+ * will be returned.
+ */
+struct dc_stream_status *dc_stream_get_status_from_state(
+	struct dc_state *state,
 	struct dc_stream_state *stream)
 {
 	uint8_t i;
-	struct dc  *dc = stream->ctx->dc;
 
-	for (i = 0; i < dc->current_state->stream_count; i++) {
-		if (stream == dc->current_state->streams[i])
-			return &dc->current_state->stream_status[i];
+	for (i = 0; i < state->stream_count; i++) {
+		if (stream == state->streams[i])
+			return &state->stream_status[i];
 	}
 
 	return NULL;
 }
 
 /**
+ * dc_stream_get_status() - Get current stream status of the given stream state
+ * @stream: The stream to get the stream status for.
+ *
+ * The given stream is expected to exist in dc->current_state. Otherwise, NULL
+ * will be returned.
+ */
+struct dc_stream_status *dc_stream_get_status(
+	struct dc_stream_state *stream)
+{
+	struct dc *dc = stream->ctx->dc;
+	return dc_stream_get_status_from_state(dc->current_state, stream);
+}
+
+/**
  * dc_stream_set_cursor_attributes() - Update cursor attributes and set cursor surface address
  */
 bool dc_stream_set_cursor_attributes(