Re: [PATCH] pmdomain: core: Honour pd_ignore_unused in the sync_state power-off

[Abel Vesa]

On 26-08-30 03:51:05, Joshua Yeong wrote:
> The pd_ignore_unused command line option is documented to "keep all
> power-domains already enabled by bootloader on, even if no driver has
> claimed them". On an OF platform it no longer does.
> 
> Powering off unclaimed PM domains used to be the job of
> genpd_power_off_unused(), which bails out on the option.
> Commit 002ebddd695a ("pmdomain: core: Restore behaviour for disabling
> unused PM domains") stopped that late_initcall_sync from clearing
> stay_on, so it can no longer power off a PM domain that was found
> powered-on at initialization. The only remaining path that clears
> stay_on is ->sync_state(), and it never looked at the option, so an
> unclaimed PM domain that the bootloader left on is powered off there
> regardless.
> 
> Honour the option in the sync_state paths, for the PM domains that have
> no consumer attached. Those are the ones the option describes, and once
> genpd_power_off_unused() has bailed out they have no other power-off
> trigger, so they stay on as documented.
> 
> The stay_on constraint is dropped either way, leaving the lifetime of
> the constraint unchanged. The PM domains that do have a consumer
> attached therefore stay under the control of runtime PM, which the
> option has never covered, and a PM domain that gains a consumer after
> ->sync_state() is not left pinned.
> 
> Fixes: 0e789b491ba0 ("pmdomain: core: Leave powered-on genpds on until sync_state")
> Signed-off-by: Joshua Yeong <joshua.yeong@xxxxxxxxxxxxxxxx>

This looks OK to me, so:

Reviewed-by: Abel Vesa <abel.vesa@xxxxxxxxxxxxxxxx>