Re: EHCI and MUSB do not discover devices without CONFIG_PM

[Ladislav Michl <ladis-6z/3iImG2C8G8FEW9MqTrA@public.gmane.org>]

On Tue, Nov 28, 2017 at 06:11:31AM -0800, Tony Lindgren wrote:
> * Ladislav Michl <ladis-6z/3iImG2C8G8FEW9MqTrA@public.gmane.org> [171128 09:42]:
> > On Tue, Nov 28, 2017 at 10:30:54AM +0100, Greg KH wrote:
> > > bit-banging an ir decoder, ugh, you are in for a world of hurt.  Can't
> > > you put a chip on the device that does this for you in hardware?
> > 
> > OMAP has DM timer which can be externally trigered on edge. Perfect for
> > that purpose. But I cannot pinmux its input as hw designers did poor job.
> > And there are thousands of devices deployed.
> > 
> > So it is about a lot of soldering or providing software solution.
> > 
> > > Anyway, good luck!
> > 
> > A little pointer would increase "luck" by several order of magnitudes.
> 
> Hmm did you already try limiting cpuidle to C1 only in /sys?

I have CONFIG_CPU_IDLE=n, which should be the same. Is that right?

> From what I recall you just set the latency to less than C2
> has. The cpuidle latencies are in struct omap3_idle_statedata
> omap3_idle_data[].

I disabled cpuidle and frequency scaling completely. The only thing that
make jitter difference is CONFIG_PM (see original thread).

There's lot of pm_wkup interrupts with CONFIG_PM - order of magnitude
more than gp_timer.

	ladis
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