[PATCH v13 06/35] clk: tegra: Support runtime PM and power domain

[Dmitry Osipenko]

06.10.2021 01:19, Dmitry Osipenko пишет:
...
> I reproduced the OFF problem by removing the clk prepare/unprepare from
> the suspend/resume of the clk driver and making some extra changes to
> clock tree topology and etc to trigger the problem on Nexus 7.
> 
> tegra-pmc 7000e400.pmc: failed to turn off PM domain heg: -13
> 
> It happens from genpd_suspend_noirq() -> tegra_genpd_power_off() -> clk
> -> GENPD -> I2C -> runtime-pm.
> 
> -13 is EACCES, it comes from the runtime PM of I2C device. RPM is
> prohibited/disabled during late (NOIRQ) suspend by the drivers core.

My bad, I double-checked and it's not I2C RPM that is failing now, but
the clock's RPM [1], which is also unavailable during NOIRQ.

[1]
https://elixir.free-electrons.com/linux/v5.15-rc4/source/drivers/clk/clk.c#L116

Previously it was I2C RPM that was failing in a similar way, but code
changed a tad since that time.