Re: [PATCH] ARM: dts: ti/omap: gta04: fix pm issues caused by spi module

[Andreas Kemnade <andreas@kemnade.info>]

Am Mon, 11 Nov 2024 19:31:17 +0100
schrieb Andreas Kemnade <andreas@kemnade.info>:

> Am Mon, 11 Nov 2024 17:09:53 +0200
> schrieb Tony Lindgren <tony@atomide.com>:
> 
> > * Andreas Kemnade <andreas@kemnade.info> [241108 17:41]:  
> > > They are not used, if they are just disabled, kernel does not touch
> > > them, so if it is there, the kernel can handle
> > > pm. At least as long as it is not under ti,sysc.
> > > 
> > > There are probably cleaner solutions for this, but for a CC: stable I
> > > would prefer something less invasive.    
> > 
> > For unused devices, it's best to configure things to use ti-sysc, and
> > then set status disabled (or reserved) for the child devices only. This
> > way the parent interconnect target module is PM runtime managed by
> > Linux, and it's power domain gets properly idled for the unused devices
> > too.
> >   
> Hmm, we also have omap_hwmod_setup_all() which is still called if
> without device nodes being available.
> 
> Converting mcspi to ti-sysc is more than 100 lines. So it does not
> qualify for stable.
> 
> > > I can try a ti-sysc based fix in parallel.    
> > 
> > Yeah that should be trivial hopefully :)
> >   
> I played around, got pm issues too, tried to force-enable things (via
> power/control),
> watched CM_IDLEST1_CORE and CM_FCLKEN1_CORE, they behave. Bits are set
> or reset.
> 
> but not CM_IDLEST_CKGEN, it is 0x209 instead of 0x1.
> 
> I test from initramfs, so no mmc activity involved
> 
> removing status = "disabled" from mcspi3 solves things.
> With and without ti-sysc conversion. removing status = "disabled" from
> mcspi4 seems not to help.
> 
> That all cannot be... I will retry tomorrow.
> 
well, I tried a bit further:
I build the omap spi driver as module.
and booted With mcspi3 not disabled and no module autoload.

without module loaded: pm bad, same as with mcspi3 disabled
with module loaded: core pm ok
with module loaded and unloaded: core pm ok.

so at least a trace.

Regards,
Andreas