drm/amd/display: add option to disable DCC for DCC 128b request

1. reverts commit e67f51012740 ("dc: temp disable DCC on high res.")
- default still DCC enabled

2. add debug options to decide how DCC is disabled
- disable DCC
- disable DCC if DCC requires 128b (aka. half) request
-- observed compressed data corruption result in screen corruption in
full (256b) request while half (128b) would cause DCN to hang, result in
DF hang

Signed-off-by: Tony Cheng <tony.cheng@amd.com>
Reviewed-by: Yongqiang Sun <yongqiang.sun@amd.com>
Acked-by: Harry Wentland <Harry.Wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/amd/display/dc/dc.h b/drivers/gpu/drm/amd/display/dc/dc.h
index 622488e..d7afbcf 100644
--- a/drivers/gpu/drm/amd/display/dc/dc.h
+++ b/drivers/gpu/drm/amd/display/dc/dc.h
@@ -56,11 +56,10 @@ struct dc_caps {
 	uint32_t max_planes;
 	uint32_t max_downscale_ratio;
 	uint32_t i2c_speed_in_khz;
-
 	unsigned int max_cursor_size;
+	bool dcc_const_color;
 };
 
-
 struct dc_dcc_surface_param {
 	struct dc_size surface_size;
 	enum surface_pixel_format format;
@@ -162,6 +161,12 @@ struct dc_config {
 	bool disable_disp_pll_sharing;
 };
 
+enum dcc_option {
+	DCC_ENABLE = 0,
+	DCC_DISABLE = 1,
+	DCC_HALF_REQ_DISALBE = 2,
+};
+
 enum pipe_split_policy {
 	MPC_SPLIT_DYNAMIC = 0,
 	MPC_SPLIT_AVOID = 1,
@@ -177,7 +182,7 @@ struct dc_debug {
 	bool clock_trace;
 	bool validation_trace;
 	bool disable_stutter;
-	bool disable_dcc;
+	enum dcc_option disable_dcc;
 	bool disable_dfs_bypass;
 	bool disable_dpp_power_gate;
 	bool disable_hubp_power_gate;