linux-kernel - Re: Clock register in early init

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Date:	Tue, 22 May 2012 14:15:32 +0300
From:	Peter De Schrijver <pdeschrijver@...dia.com>
To:	"Turquette, Mike" <mturquette@...com>
CC:	Prashant Gaikwad <pgaikwad@...dia.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>
Subject: Re: Clock register in early init

On Mon, May 21, 2012 at 08:05:57PM +0200, Turquette, Mike wrote:
> On Mon, May 21, 2012 at 1:46 AM, Peter De Schrijver
> <pdeschrijver@...dia.com> wrote:
> >>
> >> On OMAP I think the only "gotcha" is setting up the timer.  One
> >> solution is to open code the register reads and the rate calculation
> >> in the timer code.  That is ugly... but it works.
> >>
> >> > Which advantages do you see in dynamically allocating all this?
> >> >
> >>
> >> There are many but I'll name a couple.  The most significant point is
> >> that we can avoid exposing the definition of struct clk if we
> >> dynamically allocate stuff.  One can use struct clk_hw_init to
> >> statically initialize data, or instead rely on direct calls to
> >> clk_register with a bunch of parameters.
> >>
> >
> > Which means if you make a mistake in specifying parents for example, it will
> > only fail at runtime, possibly before any console is active. With static
> > initialization, this will fail at compiletime. Much easier to debug.
> >
> 
> Is this really a problem?  Once you have good data it does not change.
>  Debugging bad data when introducing a new chip is just a fact of
> life.  Static versus dynamic is irrelevant here.
> 

I think it is a problem yes, especially when the tree becomes more
complicated.

Cheers,

Peter.
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