Commit 29c1c204 authored by Ryan Seto's avatar Ryan Seto Committed by Alex Deucher
Browse files

drm/amd/display: Prevent VStartup Overflow 



[Why]
For some VR headsets with large blanks, it's possible
to overflow the OTG_VSTARTUP_PARAM:VSTARTUP_START
register. This can lead to incorrect DML calculations
and underflow downstream.

[How]
Min the calcualted max_vstartup_lines with the max
value of the register.

Reviewed-by: default avatarDillon Varone <dillon.varone@amd.com>
Signed-off-by: default avatarRyan Seto <ryanseto@amd.com>
Signed-off-by: default avatarTom Chung <chiahsuan.chung@amd.com>
Tested-by: default avatarDaniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent 34935701

drivers/gpu/drm/amd/display/dc/dml2/dml21/src/dml2_core/dml2_core_dcn4_calcs.c

+2 −0
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ 
//#define DML_MODE_SUPPORT_USE_DPM_DRAM_BW

//#define DML_GLOBAL_PREFETCH_CHECK

#define ALLOW_SDPIF_RATE_LIMIT_PRE_CSTATE

#define DML_MAX_VSTARTUP_START 1023









const char *dml2_core_internal_bw_type_str(enum dml2_core_internal_bw_type bw_type)









{








@@ -3737,6 +3738,7 @@ static unsigned int CalculateMaxVStartup(







	dml2_printf("DML::%s: vblank_avail = %u\n", __func__, vblank_avail);









	dml2_printf("DML::%s: max_vstartup_lines = %u\n", __func__, max_vstartup_lines);









#endif









	max_vstartup_lines = (unsigned int)math_min2(max_vstartup_lines, DML_MAX_VSTARTUP_START);









	return max_vstartup_lines;









}