This is a note to let you know that I've just added the patch titled drm/amd/display: Fix prefetch bandwidth calculation for DCN3.1 to the 5.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drm-amd-display-fix-prefetch-bandwidth-calculation-for-dcn3.1.patch and it can be found in the queue-5.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From c938aed88f8259dc913b717a32319101c66e87a9 Mon Sep 17 00:00:00 2001 From: Nicholas Kazlauskas <nicholas.kazlauskas@xxxxxxx> Date: Wed, 29 Sep 2021 11:37:33 -0400 Subject: drm/amd/display: Fix prefetch bandwidth calculation for DCN3.1 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]), Patches currently in stable-queue which might be from nicholas.kazlauskas@xxxxxxx are queue-5.14/drm-amd-display-require-immediate-flip-support-for-dcn3.1-planes.patch queue-5.14/drm-amd-display-fallback-to-clocks-which-meet-requested-voltage-on-dcn31.patch queue-5.14/drm-amd-display-fix-prefetch-bandwidth-calculation-for-dcn3.1.patch queue-5.14/drm-amd-display-fix-deadlock-when-falling-back-to-v2-from-v3.patch