drm/amd/display: Fix max vstartup calculation for modes with borders
authorNicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Wed, 7 Jul 2021 17:19:14 +0000 (13:19 -0400)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sun, 8 Aug 2021 07:05:23 +0000 (09:05 +0200)
commit98b070694f4570908a0e8ea5afb68d81b0aa2051
treecb0685039515332ed37d8b2f213bc1442191c5cd
parentf9d875c8c92f1bdaeeb3eeccbf8402974f20cd31
drm/amd/display: Fix max vstartup calculation for modes with borders

[ Upstream commit d7940911fc0754d99b208f0e3098762d39f403a0 ]

[Why]
Vertical and horizontal borders in timings are treated as increasing the
active area - vblank and hblank actually shrink.

Our input into DML does not include these borders so it incorrectly
assumes it has more time than available for vstartup and tmdl
calculations for some modes with borders.

An example of such a timing would be 640x480@72Hz:

h_total: 832
h_border_left: 8
h_addressable: 640
h_border_right: 8
h_front_porch: 16
h_sync_width: 40
v_total: 520
v_border_top: 8
v_addressable: 480
v_border_bottom: 8
v_front_porch: 1
v_sync_width: 3
pix_clk_100hz: 315000

[How]
Include borders as part of destination vactive/hactive.

This change DCN20+ so it has wide impact, but the destination vactive
and hactive are only really used for vstartup calculation anyway.

Most modes do not have vertical or horizontal borders.

Reviewed-by: Dmytro Laktyushkin <Dmytro.Laktyushkin@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c