diff options
| author | Sung Lee <sung.lee@amd.com> | 2019-12-05 11:58:20 -0500 |
|---|---|---|
| committer | Alex Deucher <alexander.deucher@amd.com> | 2019-12-18 16:09:10 -0500 |
| commit | 760ef473f2fccdf8ca9bc0773960e16d4ce6f3d2 (patch) | |
| tree | 347f99e5d1d20cf59f804232587487f105ee0c04 /drivers/gpu/drm/amd/display/dc/dcn20 | |
| parent | 5479034576ec8b7166a66efe5de1d911feb43d4a (diff) | |
drm/amd/display: Formula refactor for calculating DPP CLK DTO
[Why]
Previous formula for calculating DPP CLK DTO was
hard to understand.
[How]
Replace with easier to understand formula that produces
same results.
Signed-off-by: Sung Lee <sung.lee@amd.com>
Reviewed-by: Dmytro Laktyushkin <Dmytro.Laktyushkin@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Diffstat (limited to 'drivers/gpu/drm/amd/display/dc/dcn20')
| -rw-r--r-- | drivers/gpu/drm/amd/display/dc/dcn20/dcn20_dccg.c | 20 |
1 files changed, 10 insertions, 10 deletions
diff --git a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_dccg.c b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_dccg.c index 1e1151356e60..50bffbfdd394 100644 --- a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_dccg.c +++ b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_dccg.c @@ -50,20 +50,20 @@ void dccg2_update_dpp_dto(struct dccg *dccg, int dpp_inst, int req_dppclk) if (dccg->ref_dppclk && req_dppclk) { int ref_dppclk = dccg->ref_dppclk; + int modulo, phase; - ASSERT(req_dppclk <= ref_dppclk); - /* need to clamp to 8 bits */ - if (ref_dppclk > 0xff) { - int divider = (ref_dppclk + 0xfe) / 0xff; + // phase / modulo = dpp pipe clk / dpp global clk + modulo = 0xff; // use FF at the end + phase = ((modulo * req_dppclk) + ref_dppclk - 1) / ref_dppclk; - ref_dppclk /= divider; - req_dppclk = (req_dppclk + divider - 1) / divider; - if (req_dppclk > ref_dppclk) - req_dppclk = ref_dppclk; + if (phase > 0xff) { + ASSERT(false); + phase = 0xff; } + REG_SET_2(DPPCLK_DTO_PARAM[dpp_inst], 0, - DPPCLK0_DTO_PHASE, req_dppclk, - DPPCLK0_DTO_MODULO, ref_dppclk); + DPPCLK0_DTO_PHASE, phase, + DPPCLK0_DTO_MODULO, modulo); REG_UPDATE(DPPCLK_DTO_CTRL, DPPCLK_DTO_ENABLE[dpp_inst], 1); } else { |