Re: [PATCH 01/48] clk: at91: replace usleep() by udelay() calls

From: Alexandre Belloni
Date: Fri Jun 10 2016 - 18:37:44 EST


On 11/06/2016 at 00:30:36 +0200, Arnd Bergmann wrote :
> On Saturday, June 11, 2016 12:03:04 AM CEST Alexandre Belloni wrote:
> > From: Cyrille Pitchen <cyrille.pitchen@xxxxxxxxx>
> >
> > Fix the main and slow clock .prepare() implementations which used to call
> > usleep() when the scheduler wasn't ready yet.
> >
>
> Does this have to be called that early? It seems wasteful to always
> call udelay() here, when these are functions that are normally
> allowed to sleep.
>

Well, the main issue here is that we want to be able to prepare_enable
the slow clock before we are allowed to sleep.

Thinking about it when writing that, I realize that when I reworked my
series, I removed the dependency between the clocksource TCB and the
slow_clock. But I guess we still have one on the main clock. I'll check
whether this is still necessary.

--
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com