| From | Greg Kroah-Hartman <> | Subject | [PATCH 5.14 052/125] drm/amd/display: increase Z9 latency to workaround underflow in Z9 | Date | Mon, 1 Nov 2021 10:17:05 +0100 |
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From: Eric Yang <Eric.Yang2@amd.com>
commit 4835ea6c173a8d8dfbfdbb21c4cd987d12681610 upstream.
[Why] Z9 latency is higher than when we originally tuned the watermark parameters, causing underflow. Increasing the value until the latency issues is resolved.
Reviewed-by: Nicholas Kazlauskas <Nicholas.Kazlauskas@amd.com> Acked-by: Agustin Gutierrez Sanchez <agustin.gutierrez@amd.com> Signed-off-by: Eric Yang <Eric.Yang2@amd.com> Tested-by: Daniel Wheeler <daniel.wheeler@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/gpu/drm/amd/display/dc/dcn31/dcn31_resource.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/gpu/drm/amd/display/dc/dcn31/dcn31_resource.c +++ b/drivers/gpu/drm/amd/display/dc/dcn31/dcn31_resource.c @@ -217,8 +217,8 @@ struct _vcs_dpi_soc_bounding_box_st dcn3 .num_states = 5, .sr_exit_time_us = 9.0, .sr_enter_plus_exit_time_us = 11.0, - .sr_exit_z8_time_us = 402.0, - .sr_enter_plus_exit_z8_time_us = 520.0, + .sr_exit_z8_time_us = 442.0, + .sr_enter_plus_exit_z8_time_us = 560.0, .writeback_latency_us = 12.0, .dram_channel_width_bytes = 4, .round_trip_ping_latency_dcfclk_cycles = 106,
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