From: Brandon Syu <Brandon.Syu@xxxxxxx> [ Upstream commit 7e0b367db85ef7b91399006253759a024eab7653 ] [Why] While booting into OS, driver updates DPP/DISP CLKs. But init clock value is zero which is invalid. [How] Get current clocks value to update init clocks. To avoid underflow. Signed-off-by: Brandon Syu <Brandon.Syu@xxxxxxx> Reviewed-by: Tony Cheng <Tony.Cheng@xxxxxxx> Acked-by: Aurabindo Pillai <aurabindo.pillai@xxxxxxx> Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- .../drm/amd/display/dc/clk_mgr/dcn21/rn_clk_mgr.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) 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 2f8fee05547ac..c001307b0a59a 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 @@ -163,8 +163,17 @@ void rn_update_clocks(struct clk_mgr *clk_mgr_base, new_clocks->dppclk_khz = 100000; } - if (should_set_clock(safe_to_lower, new_clocks->dppclk_khz, clk_mgr->base.clks.dppclk_khz)) { - if (clk_mgr->base.clks.dppclk_khz > new_clocks->dppclk_khz) + /* + * Temporally ignore thew 0 cases for disp and dpp clks. + * We may have a new feature that requires 0 clks in the future. + */ + if (new_clocks->dppclk_khz == 0 || new_clocks->dispclk_khz == 0) { + new_clocks->dppclk_khz = clk_mgr_base->clks.dppclk_khz; + new_clocks->dispclk_khz = clk_mgr_base->clks.dispclk_khz; + } + + if (should_set_clock(safe_to_lower, new_clocks->dppclk_khz, clk_mgr_base->clks.dppclk_khz)) { + if (clk_mgr_base->clks.dppclk_khz > new_clocks->dppclk_khz) dpp_clock_lowered = true; clk_mgr_base->clks.dppclk_khz = new_clocks->dppclk_khz; update_dppclk = true; -- 2.27.0