From: Ryan Seto ryanseto@amd.com
[ Upstream commit 29c1c20496a7a9bafe2bc2f833d69aa52e0f2c2d ]
[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: Dillon Varone dillon.varone@amd.com Signed-off-by: Ryan Seto ryanseto@amd.com Signed-off-by: Tom Chung chiahsuan.chung@amd.com Tested-by: Daniel Wheeler daniel.wheeler@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Sasha Levin sashal@kernel.org --- .../display/dc/dml2/dml21/src/dml2_core/dml2_core_dcn4_calcs.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/gpu/drm/amd/display/dc/dml2/dml21/src/dml2_core/dml2_core_dcn4_calcs.c b/drivers/gpu/drm/amd/display/dc/dml2/dml21/src/dml2_core/dml2_core_dcn4_calcs.c index 8ed49a9df3780..c1ff869512f27 100644 --- a/drivers/gpu/drm/amd/display/dc/dml2/dml21/src/dml2_core/dml2_core_dcn4_calcs.c +++ b/drivers/gpu/drm/amd/display/dc/dml2/dml21/src/dml2_core/dml2_core_dcn4_calcs.c @@ -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) { @@ -3726,6 +3727,7 @@ 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; }