[PATCH 17/20] drm/amd/display: Use the correct max downscaling value for DCN3.x family

[Stylon Wang]

From: Nikola Cornij <nikola.cornij at amd.com>

[why]
As per spec, DCN3.x can do 6:1 downscaling and DCN2.x can do 4:1. The
max downscaling limit value for DCN2.x is 250, which means it's
calculated as 1000 / 4 = 250. For DCN3.x this then gives 1000 / 6 = 167.

[how]
Set maximum downscaling limit to 167 for DCN3.x

Signed-off-by: Nikola Cornij <nikola.cornij at amd.com>
Reviewed-by: Charlene Liu <Charlene.Liu at amd.com>
Reviewed-by: Harry Wentland <Harry.Wentland at amd.com>
Acked-by: Stylon Wang <stylon.wang at amd.com>
---
 drivers/gpu/drm/amd/display/dc/dcn30/dcn30_resource.c   | 7 ++++---
 drivers/gpu/drm/amd/display/dc/dcn301/dcn301_resource.c | 7 ++++---
 drivers/gpu/drm/amd/display/dc/dcn302/dcn302_resource.c | 7 ++++---
 3 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/dcn30/dcn30_resource.c b/drivers/gpu/drm/amd/display/dc/dcn30/dcn30_resource.c
index 45f96221a094..9109e2433965 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn30/dcn30_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn30/dcn30_resource.c
@@ -826,10 +826,11 @@ static const struct dc_plane_cap plane_cap = {
 			.fp16 = 16000
 	},
 
+	/* 6:1 downscaling ratio: 1000/6 = 166.666 */
 	.max_downscale_factor = {
-			.argb8888 = 600,
-			.nv12 = 600,
-			.fp16 = 600
+			.argb8888 = 167,
+			.nv12 = 167,
+			.fp16 = 167
 	}
 };
 
diff --git a/drivers/gpu/drm/amd/display/dc/dcn301/dcn301_resource.c b/drivers/gpu/drm/amd/display/dc/dcn301/dcn301_resource.c
index 2127399cf464..63b09c1124c4 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn301/dcn301_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn301/dcn301_resource.c
@@ -843,10 +843,11 @@ static const struct dc_plane_cap plane_cap = {
 			.fp16 = 16000
 	},
 
+	/* 6:1 downscaling ratio: 1000/6 = 166.666 */
 	.max_downscale_factor = {
-			.argb8888 = 600,
-			.nv12 = 600,
-			.fp16 = 600
+			.argb8888 = 167,
+			.nv12 = 167,
+			.fp16 = 167 
 	},
 	64,
 	64
diff --git a/drivers/gpu/drm/amd/display/dc/dcn302/dcn302_resource.c b/drivers/gpu/drm/amd/display/dc/dcn302/dcn302_resource.c
index fc2dea243d1b..a33f0365329b 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn302/dcn302_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn302/dcn302_resource.c
@@ -284,10 +284,11 @@ static const struct dc_plane_cap plane_cap = {
 				.nv12 = 16000,
 				.fp16 = 16000
 		},
+		/* 6:1 downscaling ratio: 1000/6 = 166.666 */
 		.max_downscale_factor = {
-				.argb8888 = 600,
-				.nv12 = 600,
-				.fp16 = 600
+				.argb8888 = 167,
+				.nv12 = 167,
+				.fp16 = 167
 		},
 		16,
 		16
-- 
2.25.1