From: Alvin Lee Alvin.Lee2@amd.com
commit b504f99ccaa64da364443431e388ecf30b604e38 upstream.
[Description] - Due to bandwidth / arbitration issues at 200Mhz DCFCLK, we want to enforce minimum 60us of prefetch to avoid intermittent underflow issues - Since 60us prefetch is already enforced for UCLK DPM0, and many DCFCLK's > 200Mhz are mapped to UCLK DPM1, in theory there should not be any UCLK DPM regressions by enforcing greater prefetch
Reviewed-by: Nevenko Stupar Nevenko.Stupar@amd.com Reviewed-by: Jun Lei Jun.Lei@amd.com Cc: Mario Limonciello mario.limonciello@amd.com Cc: Alex Deucher alexander.deucher@amd.com Cc: stable@vger.kernel.org Acked-by: Alex Hung alex.hung@amd.com Signed-off-by: Alvin Lee Alvin.Lee2@amd.com Tested-by: Daniel Wheeler daniel.wheeler@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/gpu/drm/amd/display/dc/dml/dcn32/display_mode_vba_32.c | 5 +++-- drivers/gpu/drm/amd/display/dc/dml/dcn32/display_mode_vba_32.h | 1 + 2 files changed, 4 insertions(+), 2 deletions(-)
--- a/drivers/gpu/drm/amd/display/dc/dml/dcn32/display_mode_vba_32.c +++ b/drivers/gpu/drm/amd/display/dc/dml/dcn32/display_mode_vba_32.c @@ -810,7 +810,8 @@ static void DISPCLKDPPCLKDCFCLKDeepSleep v->SwathHeightY[k], v->SwathHeightC[k], TWait, - v->DRAMSpeedPerState[mode_lib->vba.VoltageLevel] <= MEM_STROBE_FREQ_MHZ ? + (v->DRAMSpeedPerState[mode_lib->vba.VoltageLevel] <= MEM_STROBE_FREQ_MHZ || + v->DCFCLKPerState[mode_lib->vba.VoltageLevel] <= MIN_DCFCLK_FREQ_MHZ) ? mode_lib->vba.ip.min_prefetch_in_strobe_us : 0, /* Output */ &v->DSTXAfterScaler[k], @@ -3309,7 +3310,7 @@ void dml32_ModeSupportAndSystemConfigura v->swath_width_chroma_ub_this_state[k], v->SwathHeightYThisState[k], v->SwathHeightCThisState[k], v->TWait, - v->DRAMSpeedPerState[i] <= MEM_STROBE_FREQ_MHZ ? + (v->DRAMSpeedPerState[i] <= MEM_STROBE_FREQ_MHZ || v->DCFCLKState[i][j] <= MIN_DCFCLK_FREQ_MHZ) ? mode_lib->vba.ip.min_prefetch_in_strobe_us : 0,
/* Output */ --- a/drivers/gpu/drm/amd/display/dc/dml/dcn32/display_mode_vba_32.h +++ b/drivers/gpu/drm/amd/display/dc/dml/dcn32/display_mode_vba_32.h @@ -53,6 +53,7 @@ #define BPP_BLENDED_PIPE 0xffffffff
#define MEM_STROBE_FREQ_MHZ 1600 +#define MIN_DCFCLK_FREQ_MHZ 200 #define MEM_STROBE_MAX_DELIVERY_TIME_US 60.0
struct display_mode_lib;