drm/amd/display: Add force detile buffer size debug flag

[WHY]
Allow changing DET size with debug flag for testing purposes
Reviewed-by: Nicholas Kazlauskas <Nicholas.Kazlauskas@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Michael Strauss <michael.strauss@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -75,6 +75,16 @@ enum dc_plane_type {
 	DC_PLANE_TYPE_DCN_UNIVERSAL,
 };
 
+// Sizes defined as multiples of 64KB
+enum det_size {
+	DET_SIZE_DEFAULT = 0,
+	DET_SIZE_192KB = 3,
+	DET_SIZE_256KB = 4,
+	DET_SIZE_320KB = 5,
+	DET_SIZE_384KB = 6
+};
+
+
 struct dc_plane_cap {
 	enum dc_plane_type type;
 	uint32_t blends_with_above : 1;
@@ -692,6 +702,8 @@ struct dc_debug_options {
 	/* FEC/PSR1 sequence enable delay in 100us */
 	uint8_t fec_enable_delay_in100us;
 	bool enable_driver_sequence_debug;
+	enum det_size crb_alloc_policy;
+	int crb_alloc_policy_min_disp_count;
 #if defined(CONFIG_DRM_AMD_DC_DCN)
 	bool disable_z10;
 	bool enable_sw_cntl_psr;

drivers/gpu/drm/amd/display/dc/dcn31/dcn31_resource.c

@@ -1830,6 +1830,9 @@ static int dcn31_populate_dml_pipes_from_context(
 			context->bw_ctx.dml.ip.det_buffer_size_kbytes = 192;
 			pipes[0].pipe.src.unbounded_req_mode = true;
 		}
+	} else if (context->stream_count >= dc->debug.crb_alloc_policy_min_disp_count
+			&& dc->debug.crb_alloc_policy > DET_SIZE_DEFAULT) {
+		context->bw_ctx.dml.ip.det_buffer_size_kbytes = dc->debug.crb_alloc_policy * 64;
 	}
 
 	return pipe_cnt;