[PATCH AUTOSEL 6.0 22/30] drm/amd/display: Fix DCN32 DSC delay calculation

Sasha Levin sashal at kernel.org
Fri Nov 11 02:33:30 UTC 2022


From: George Shen <george.shen at amd.com>

[ Upstream commit bad610c97c08eef3ed1fa769a8b08b94f95b451e ]

[Why]
DCN32 DSC delay calculation had an unintentional integer division,
resulting in a mismatch against the DML spreadsheet.

[How]
Cast numerator to double before performing the division.

Reviewed-by: Alvin Lee <Alvin.Lee2 at amd.com>
Acked-by: Alex Hung <alex.hung at amd.com>
Signed-off-by: George Shen <george.shen at amd.com>
Tested-by: Mark Broadworth <mark.broadworth at amd.com>
Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
Signed-off-by: Sasha Levin <sashal at kernel.org>
---
 .../gpu/drm/amd/display/dc/dml/dcn32/display_mode_vba_util_32.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/dc/dml/dcn32/display_mode_vba_util_32.c b/drivers/gpu/drm/amd/display/dc/dml/dcn32/display_mode_vba_util_32.c
index 365d290bba99..67af8f4df8b8 100644
--- a/drivers/gpu/drm/amd/display/dc/dml/dcn32/display_mode_vba_util_32.c
+++ b/drivers/gpu/drm/amd/display/dc/dml/dcn32/display_mode_vba_util_32.c
@@ -1746,7 +1746,7 @@ unsigned int dml32_DSCDelayRequirement(bool DSCEnabled,
 		}
 
 		DSCDelayRequirement_val = DSCDelayRequirement_val + (HTotal - HActive) *
-				dml_ceil(DSCDelayRequirement_val / HActive, 1);
+				dml_ceil((double)DSCDelayRequirement_val / HActive, 1);
 
 		DSCDelayRequirement_val = DSCDelayRequirement_val * PixelClock / PixelClockBackEnd;
 
-- 
2.35.1



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