From: jsg <jsg@openbsd.org>
Date: Thu, 23 Feb 2023 02:13:24 +0000 (+0000)
Subject: drm/amd/display: Adjust downscaling limits for dcn314
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=318b29720eae111ed9a57d7374bbd609244bed6e;p=openbsd

drm/amd/display: Adjust downscaling limits for dcn314

From Daniel Miess
7dbd205349f1fb098057c28a9a2af244aa868f72 in linux-6.1.y/6.1.13
dd2db2dc4bd298f33dea50c80c3c11bee4e3b0a4 in mainline linux
---

diff --git a/sys/dev/pci/drm/amd/display/dc/dcn314/dcn314_resource.c b/sys/dev/pci/drm/amd/display/dc/dcn314/dcn314_resource.c
index 9066c511a05..c80c8c8f51e 100644
--- a/sys/dev/pci/drm/amd/display/dc/dcn314/dcn314_resource.c
+++ b/sys/dev/pci/drm/amd/display/dc/dcn314/dcn314_resource.c
@@ -871,8 +871,9 @@ static const struct dc_plane_cap plane_cap = {
 	},
 
 	// 6:1 downscaling ratio: 1000/6 = 166.666
+	// 4:1 downscaling ratio for ARGB888 to prevent underflow during P010 playback: 1000/4 = 250
 	.max_downscale_factor = {
-			.argb8888 = 167,
+			.argb8888 = 250,
 			.nv12 = 167,
 			.fp16 = 167
 	},
@@ -1755,7 +1756,7 @@ static bool dcn314_resource_construct(
 	pool->base.underlay_pipe_index = NO_UNDERLAY_PIPE;
 	pool->base.pipe_count = pool->base.res_cap->num_timing_generator;
 	pool->base.mpcc_count = pool->base.res_cap->num_timing_generator;
-	dc->caps.max_downscale_ratio = 600;
+	dc->caps.max_downscale_ratio = 400;
 	dc->caps.i2c_speed_in_khz = 100;
 	dc->caps.i2c_speed_in_khz_hdcp = 100;
 	dc->caps.max_cursor_size = 256;