On Mon, 4 Feb 2019 07:56:04 -0800 Tony Lindgren <tony@xxxxxxxxxxx> wrote: > * Andreas Kemnade <andreas@xxxxxxxxxxxx> [190202 06:01]: > > Enabling off mode was only reachable deeply hidden > > in the debugfs. As powersaving is an important feature, > > move the option out of its shady place. > > How about let's enable always if we have the twl4030 > configured to allow it? You can just check if the dts has > "ti,twl4030-power-idle" or "ti,twl4030-power-idle-osc-off" > properties set. > > In order to enable deeper idle states, the user space still > needs to idle the UARTs and possibly other hardware blocking > idle. So we should be safe there. > Let us not mix up runtime pm and system pm. The uarts need to be idled for runtime suspend, but they are off/ret for system suspend without userspace intervention, so allowing off mode will have an influence even without uart runtime suspend, and also probably for other powerdomains (non-core/per). So we still need to be sure to handle at least some erratas and context save/restore correctly. Your Idea seems to be in pseudocode if (powersaving_wanted) enable_off_mode() I had something in mind like if (system_is_trusted_to_handle_offmode() enable_off_mode() Regards, Andreas
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