[PATCH 5.14 051/125] drm/amd/display: Fix prefetch bandwidth calculation for DCN3.1

From: Greg Kroah-Hartman
Date: Mon Nov 01 2021 - 05:43:50 EST


From: Nicholas Kazlauskas <nicholas.kazlauskas@xxxxxxx>

commit c938aed88f8259dc913b717a32319101c66e87a9 upstream.

[Why]
Prefetch BW calculated is lower than the DML reference because of a
porting error that's excluding cursor and row bandwidth from the
pixel data bandwidth.

[How]
Change the dml_max4 to dml_max3 and include cursor and row bandwidth
in the same calculation as the rest of the pixel data during vactive.

Reviewed-by: Dmytro Laktyushkin <Dmytro.Laktyushkin@xxxxxxx>
Acked-by: Agustin Gutierrez Sanchez <agustin.gutierrez@xxxxxxx>
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@xxxxxxx>
Tested-by: Daniel Wheeler <daniel.wheeler@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/amd/display/dc/dml/dcn31/display_mode_vba_31.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

--- a/drivers/gpu/drm/amd/display/dc/dml/dcn31/display_mode_vba_31.c
+++ b/drivers/gpu/drm/amd/display/dc/dml/dcn31/display_mode_vba_31.c
@@ -5399,9 +5399,9 @@ void dml31_ModeSupportAndSystemConfigura

v->MaximumReadBandwidthWithPrefetch =
v->MaximumReadBandwidthWithPrefetch
- + dml_max4(
- v->VActivePixelBandwidth[i][j][k],
- v->VActiveCursorBandwidth[i][j][k]
+ + dml_max3(
+ v->VActivePixelBandwidth[i][j][k]
+ + v->VActiveCursorBandwidth[i][j][k]
+ v->NoOfDPP[i][j][k]
* (v->meta_row_bandwidth[i][j][k]
+ v->dpte_row_bandwidth[i][j][k]),