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 9066c51..c80c8c8 100644 (file)
--- 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;