[7.1-rc1 BUG] System hang when reading clock controller sysfs 'registers' files

[Daniel J Blueman]

On a Qualcomm X1 Hamoa-based Lenovo Slim7x with upstream 7.1-rc1, when
reading any of the /sys/kernel/debug/regmap/*clock*/registers files
[1] (which could happen inadvertently with grep), we see a complete
and immediate system hang.

If this relates to clock/power gating, it could be avoided by
inhibiting that prior to the read. It also reproduces when booted with
"clk_ignore_unused pd_ignore_unused".

Thanks,
  Dan

-- [1]

/sys/kernel/debug/regmap/100000.clock-controller/registers
/sys/kernel/debug/regmap/1fc0000.clock-controller/registers
/sys/kernel/debug/regmap/3d90000.clock-controller/registers
/sys/kernel/debug/regmap/6b6c000.clock-controller-lpass-audio-csr/registers
/sys/kernel/debug/regmap/6ea0000.clock-controller-lpass-tcsr/registers
/sys/kernel/debug/regmap/aaf0000.clock-controller/registers
/sys/kernel/debug/regmap/af00000.clock-controller/registers
/sys/kernel/debug/regmap/dummy-clock-controller@0x0000000001fc0000/registers
--
Daniel J Blueman