[PATCH 5.5 160/399] drm/amd/display: Lower DPP DTO only when safe

Greg Kroah-Hartman
2020-02-21T07:52:08Z

From: Sung Lee <sung.lee@amd.com>

[ Upstream commit 5479034576ec8b7166a66efe5de1d911feb43d4a ]

[Why]
A corner case currently exists where DPP DTO is lowered before
pipes are updated to a higher viewport. This causes underflow
as the DPPCLK is too low for the current viewport.

[How]
Only lower DPP DTO when it is safe to lower, or if
the newer clocks are higher than the current ones.

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
.../amd/display/dc/clk_mgr/dcn20/dcn20_clk_mgr.c | 16 ++++++++++------
.../amd/display/dc/clk_mgr/dcn20/dcn20_clk_mgr.h | 2 +-
.../amd/display/dc/clk_mgr/dcn21/rn_clk_mgr.c | 8 ++++----
3 files changed, 15 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn20/dcn20_clk_mgr.c b/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn20/dcn20_clk_mgr.c
index 25d7b7c6681cc..7dca2e6eb3bc9 100644
--- a/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn20/dcn20_clk_mgr.c
+++ b/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn20/dcn20_clk_mgr.c
@@ -100,13 +100,13 @@ uint32_t dentist_get_did_from_divider(int divider)
}

void dcn20_update_clocks_update_dpp_dto(struct clk_mgr_internal *clk_mgr,
- struct dc_state *context)
+ struct dc_state *context, bool safe_to_lower)
{
int i;

clk_mgr->dccg->ref_dppclk = clk_mgr->base.clks.dppclk_khz;
for (i = 0; i < clk_mgr->base.ctx->dc->res_pool->pipe_count; i++) {
- int dpp_inst, dppclk_khz;
+ int dpp_inst, dppclk_khz, prev_dppclk_khz;

/* Loop index will match dpp->inst if resource exists,
* and we want to avoid dependency on dpp object
@@ -114,8 +114,12 @@ void dcn20_update_clocks_update_dpp_dto(struct clk_mgr_internal *clk_mgr,
dpp_inst = i;
dppclk_khz = context->res_ctx.pipe_ctx[i].plane_res.bw.dppclk_khz;

- clk_mgr->dccg->funcs->update_dpp_dto(
- clk_mgr->dccg, dpp_inst, dppclk_khz);
+ prev_dppclk_khz = clk_mgr->base.ctx->dc->current_state->res_ctx.pipe_ctx[i].plane_res.bw.dppclk_khz;
+
+ if (safe_to_lower || prev_dppclk_khz < dppclk_khz) {
+ clk_mgr->dccg->funcs->update_dpp_dto(
+ clk_mgr->dccg, dpp_inst, dppclk_khz);
+ }
}
}

@@ -240,7 +244,7 @@ void dcn2_update_clocks(struct clk_mgr *clk_mgr_base,
if (dc->config.forced_clocks == false || (force_reset && safe_to_lower)) {
if (dpp_clock_lowered) {
// if clock is being lowered, increase DTO before lowering refclk
- dcn20_update_clocks_update_dpp_dto(clk_mgr, context);
+ dcn20_update_clocks_update_dpp_dto(clk_mgr, context, safe_to_lower);
dcn20_update_clocks_update_dentist(clk_mgr);
} else {
// if clock is being raised, increase refclk before lowering DTO
@@ -248,7 +252,7 @@ void dcn2_update_clocks(struct clk_mgr *clk_mgr_base,
dcn20_update_clocks_update_dentist(clk_mgr);
// always update dtos unless clock is lowered and not safe to lower
if (new_clocks->dppclk_khz >= dc->current_state->bw_ctx.bw.dcn.clk.dppclk_khz)
- dcn20_update_clocks_update_dpp_dto(clk_mgr, context);
+ dcn20_update_clocks_update_dpp_dto(clk_mgr, context, safe_to_lower);
}
}

diff --git a/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn20/dcn20_clk_mgr.h b/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn20/dcn20_clk_mgr.h
index c9fd824f3c231..74ccd6c04134a 100644
--- a/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn20/dcn20_clk_mgr.h
+++ b/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn20/dcn20_clk_mgr.h
@@ -34,7 +34,7 @@ void dcn2_update_clocks_fpga(struct clk_mgr *clk_mgr,
struct dc_state *context,
bool safe_to_lower);
void dcn20_update_clocks_update_dpp_dto(struct clk_mgr_internal *clk_mgr,
- struct dc_state *context);
+ struct dc_state *context, bool safe_to_lower);

void dcn2_init_clocks(struct clk_mgr *clk_mgr);

diff --git a/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn21/rn_clk_mgr.c b/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn21/rn_clk_mgr.c
index 35c55e54eac01..dbf063856846e 100644
--- a/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn21/rn_clk_mgr.c
+++ b/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn21/rn_clk_mgr.c
@@ -164,16 +164,16 @@ void rn_update_clocks(struct clk_mgr *clk_mgr_base,
}

if (dpp_clock_lowered) {
- // if clock is being lowered, increase DTO before lowering refclk
- dcn20_update_clocks_update_dpp_dto(clk_mgr, context);
+ // increase per DPP DTO before lowering global dppclk
+ dcn20_update_clocks_update_dpp_dto(clk_mgr, context, safe_to_lower);
rn_vbios_smu_set_dppclk(clk_mgr, clk_mgr_base->clks.dppclk_khz);
} else {
- // if clock is being raised, increase refclk before lowering DTO
+ // increase global DPPCLK before lowering per DPP DTO
if (update_dppclk || update_dispclk)
rn_vbios_smu_set_dppclk(clk_mgr, clk_mgr_base->clks.dppclk_khz);
// always update dtos unless clock is lowered and not safe to lower
if (new_clocks->dppclk_khz >= dc->current_state->bw_ctx.bw.dcn.clk.dppclk_khz)
- dcn20_update_clocks_update_dpp_dto(clk_mgr, context);
+ dcn20_update_clocks_update_dpp_dto(clk_mgr, context, safe_to_lower);
}

if (update_dispclk &&
--
2.20.1