Messages in this thread | | | Subject | Re: [PATCH v2] clk: mediatek: clk-mux: Add .determine_rate() callback | From | Stephen Boyd <> | Date | Fri, 14 Oct 2022 13:38:37 -0700 |
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Quoting AngeloGioacchino Del Regno (2022-10-11 06:55:48) > Since commit 262ca38f4b6e ("clk: Stop forwarding clk_rate_requests > to the parent"), the clk_rate_request is .. as the title says, not > forwarded anymore to the parent: this produces an issue with the > MediaTek clock MUX driver during GPU DVFS on MT8195, but not on > MT8192 or others. > > This is because, differently from others, like MT8192 where all of > the clocks in the MFG parents tree are of mtk_mux type, but in the > parent tree of MT8195's MFG clock, we have one mtk_mux clock and > one (clk framework generic) mux clock, like so: > > names: mfg_bg3d -> mfg_ck_fast_ref -> top_mfg_core_tmp (or) mfgpll > types: mtk_gate -> mux -> mtk_mux (or) mtk_pll > > To solve this issue and also keep the GPU DVFS clocks code working > as expected, wire up a .determine_rate() callback for the mtk_mux > ops; for that, the standard clk_mux_determine_rate_flags() was used > as it was possible to. > > This commit was successfully tested on MT6795 Xperia M5, MT8173 Elm, > MT8192 Spherion and MT8195 Tomato; no regressions were seen. > > For the sake of some more documentation about this issue here's the > trace of it: >
Applied to clk-next
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