drm/amd/display: Enable new commit sequence only for DCN32x

Change commit sequence will impact all ASICs. It is prudent to run this
update in small steps to keep issues under control and avoid any
potential regression. With this idea in mind, this commit is preparation
work for the complete transition to the new commit sequence. To maintain
this change manageable across multiple ASICs, this commit adds a new
function named dc_commit_streams which is a copy of the dc_commit_state
with some minor changes. Finally, inside the dc_commit_state, we check
if we are using DCN32x or above and enable the new sequence only for
those devices.
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Co-developed-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/core/dc.c

@@ -1890,11 +1890,57 @@ static enum dc_status dc_commit_state_no_check(struct dc *dc, struct dc_state *c
 	return result;
 }
 
+enum dc_status dc_commit_streams(struct dc *dc, struct dc_state *context)
+{
+	enum dc_status res = DC_OK;
+	int i;
+
+	if (!streams_changed(dc, context->streams, context->stream_count))
+		return res;
+
+	DC_LOG_DC("%s: %d streams\n",
+				__func__, context->stream_count);
+
+	for (i = 0; i < context->stream_count; i++) {
+		struct dc_stream_state *stream = context->streams[i];
+
+		dc_stream_log(dc, stream);
+	}
+
+	/*
+	 * Previous validation was perfomred with fast_validation = true and
+	 * the full DML state required for hardware programming was skipped.
+	 *
+	 * Re-validate here to calculate these parameters / watermarks.
+	 */
+	res = dc_validate_global_state(dc, context, false);
+	if (res != DC_OK) {
+		DC_LOG_ERROR("DC commit global validation failure: %s (%d)",
+			     dc_status_to_str(res), res);
+		return res;
+	}
+
+	res = dc_commit_state_no_check(dc, context);
+
+	return (res == DC_OK);
+}
+
+/* TODO: When the transition to the new commit sequence is done, remove this
+ * function in favor of dc_commit_streams. */
 bool dc_commit_state(struct dc *dc, struct dc_state *context)
 {
 	enum dc_status result = DC_ERROR_UNEXPECTED;
 	int i;
 
+	/* TODO: Since change commit sequence can have a huge impact,
+	 * we decided to only enable it for DCN3x. However, as soon as
+	 * we get more confident about this change we'll need to enable
+	 * the new sequence for all ASICs. */
+	if (dc->ctx->dce_version >= DCN_VERSION_3_2) {
+		result = dc_commit_streams(dc, context);
+		return result == DC_OK;
+	}
+
 	if (!streams_changed(dc, context->streams, context->stream_count))
 		return DC_OK;
 

drivers/gpu/drm/amd/display/dc/dc.h

@@ -1321,15 +1321,10 @@ void dc_resource_state_destruct(struct dc_state *context);
 
 bool dc_resource_is_dsc_encoding_supported(const struct dc *dc);
 
-/*
- * TODO update to make it about validation sets
- * Set up streams and links associated to drive sinks
- * The streams parameter is an absolute set of all active streams.
- *
- * After this call:
- *   Phy, Encoder, Timing Generator are programmed and enabled.
- *   New streams are enabled with blank stream; no memory read.
- */
+enum dc_status dc_commit_streams(struct dc *dc, struct dc_state *context);
+
+/* TODO: When the transition to the new commit sequence is done, remove this
+ * function in favor of dc_commit_streams. */
 bool dc_commit_state(struct dc *dc, struct dc_state *context);
 
 struct dc_state *dc_create_state(struct dc *dc);