From 49d5f97be648a6135d43dd7c5293a18e9ad4c7d7 Mon Sep 17 00:00:00 2001 From: Nicholas Kazlauskas Date: Fri, 28 Apr 2023 11:23:50 -0400 Subject: [PATCH] drm/amd/display: Skip DPP DTO update if root clock is gated [ Upstream commit 30f90f3c1c2c63c2fa44f61233737d27b72637c2 ] [Why] Hardware implements root clock gating by utilizing the DPP DTO registers with a special case of DTO enabled, phase = 0, modulo = 1. This conflicts with our policy to always update the DPPDTO for cases where it's expected to be disabled. The pipes unexpectedly enter a higher power state than expected because of this programming flow. [How] Guard the upper layers of HWSS against this hardware quirk with programming the register with an internal state flag in DCCG. While technically acting as global state for the DCCG, HWSS shouldn't be expected to understand the hardware quirk for having DTO disabled causing more power than DTO enabled with this specific setting. This also prevents sequencing errors from occuring in the future if we have to program DPP DTO in multiple locations. Acked-by: Stylon Wang Signed-off-by: Nicholas Kazlauskas Reviewed-by: Jun Lei Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin --- drivers/gpu/drm/amd/display/dc/dcn31/dcn31_dccg.c | 8 ++++++++ drivers/gpu/drm/amd/display/dc/dcn314/dcn314_dccg.c | 5 +++++ drivers/gpu/drm/amd/display/dc/inc/hw/dccg.h | 1 + 3 files changed, 14 insertions(+) diff --git a/drivers/gpu/drm/amd/display/dc/dcn31/dcn31_dccg.c b/drivers/gpu/drm/amd/display/dc/dcn31/dcn31_dccg.c index 4c2fdfea162f..65c1d754e2d6 100644 --- a/drivers/gpu/drm/amd/display/dc/dcn31/dcn31_dccg.c +++ b/drivers/gpu/drm/amd/display/dc/dcn31/dcn31_dccg.c @@ -47,6 +47,14 @@ void dccg31_update_dpp_dto(struct dccg *dccg, int dpp_inst, int req_dppclk) { struct dcn_dccg *dccg_dcn = TO_DCN_DCCG(dccg); + if (dccg->dpp_clock_gated[dpp_inst]) { + /* + * Do not update the DPPCLK DTO if the clock is stopped. + * It is treated the same as if the pipe itself were in PG. + */ + return; + } + if (dccg->ref_dppclk && req_dppclk) { int ref_dppclk = dccg->ref_dppclk; int modulo, phase; diff --git a/drivers/gpu/drm/amd/display/dc/dcn314/dcn314_dccg.c b/drivers/gpu/drm/amd/display/dc/dcn314/dcn314_dccg.c index de7bfba2c179..6ba24d5848b2 100644 --- a/drivers/gpu/drm/amd/display/dc/dcn314/dcn314_dccg.c +++ b/drivers/gpu/drm/amd/display/dc/dcn314/dcn314_dccg.c @@ -322,6 +322,9 @@ static void dccg314_dpp_root_clock_control( { struct dcn_dccg *dccg_dcn = TO_DCN_DCCG(dccg); + if (dccg->dpp_clock_gated[dpp_inst] == clock_on) + return; + if (clock_on) { /* turn off the DTO and leave phase/modulo at max */ REG_UPDATE(DPPCLK_DTO_CTRL, DPPCLK_DTO_ENABLE[dpp_inst], 0); @@ -335,6 +338,8 @@ static void dccg314_dpp_root_clock_control( DPPCLK0_DTO_PHASE, 0, DPPCLK0_DTO_MODULO, 1); } + + dccg->dpp_clock_gated[dpp_inst] = !clock_on; } static const struct dccg_funcs dccg314_funcs = { diff --git a/drivers/gpu/drm/amd/display/dc/inc/hw/dccg.h b/drivers/gpu/drm/amd/display/dc/inc/hw/dccg.h index ad6acd1b34e1..9651cccb084a 100644 --- a/drivers/gpu/drm/amd/display/dc/inc/hw/dccg.h +++ b/drivers/gpu/drm/amd/display/dc/inc/hw/dccg.h @@ -68,6 +68,7 @@ struct dccg { const struct dccg_funcs *funcs; int pipe_dppclk_khz[MAX_PIPES]; int ref_dppclk; + bool dpp_clock_gated[MAX_PIPES]; //int dtbclk_khz[MAX_PIPES];/* TODO needs to be removed */ //int audio_dtbclk_khz;/* TODO needs to be removed */ //int ref_dtbclk_khz;/* TODO needs to be removed */