On 09.02.2021 08:48, Stephen Boyd wrote: > Quoting (2021-01-31 09:04:28) >> This clock must be always enabled to allow access to any registers in >> fsys1 CMU. Until proper solution based on runtime PM is applied >> (similar to what was done for Exynos5433), fix this by calling >> clk_prepare_enable() directly from clock provider driver. >> >> It was observed on Samsung Galaxy S6 device (based on Exynos7420), where >> UFS module is probed before pmic used to power that device. >> In this case defer probe was happening and that clock was disabled by >> UFS driver, causing whole boot to hang on next CMU access. >> > > Does this need a Fixes tag? That would be Fixes: 753195a749a6 ("clk: samsung: exynos7: Correct CMU_FSYS1 clocks names") i.e. commit that introduced definition of the clock. But the fix cannot be backported that far as build fails with an error: drivers/clk/samsung/clk-exynos7.c: In function ‘exynos7_clk_top1_init’: drivers/clk/samsung/clk-exynos7.c:554:21: error: ‘struct clk_onecell_data’ has no member named ‘hws’ 554 | hws = ctx->clk_data.hws; It could only by backported up to: ecb1f1f7311f ("clk: samsung: Convert common drivers to the new clk_hw API") We need a different patch to fix it properly in stable kernels. And dts for board this bugfix patch was prepared is not upstream yet.