linux-kernel - Re: [PATCH v2 06/14] ARM: sun8i: clk: Add clk-factor rate application method

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Message-ID: <643c2648-ddd6-700a-68c0-2981134965c0@megous.com>
Date:	Fri, 1 Jul 2016 08:34:21 +0200
From:	Ondřej Jirman <megous@...ous.com>
To:	Jean-Francois Moine <moinejf@...e.fr>
Cc:	Maxime Ripard <maxime.ripard@...e-electrons.com>,
	Mark Rutland <mark.rutland@....com>,
	"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
	<devicetree@...r.kernel.org>, dev@...ux-sunxi.org,
	Michael Turquette <mturquette@...libre.com>,
	Stephen Boyd <sboyd@...eaurora.org>,
	open list <linux-kernel@...r.kernel.org>,
	Emilio López <emilio@...pez.com.ar>,
	Chen-Yu Tsai <wens@...e.org>, Rob Herring <robh+dt@...nel.org>,
	"open list:COMMON CLK FRAMEWORK" <linux-clk@...r.kernel.org>,
	linux-arm-kernel@...ts.infradead.org
Subject: Re: [PATCH v2 06/14] ARM: sun8i: clk: Add clk-factor rate application
 method

On 1.7.2016 07:37, Jean-Francois Moine wrote:
> On Fri, 1 Jul 2016 02:50:57 +0200
> Ondřej Jirman <megous@...ous.com> wrote:
> 
>>> Since this is really specific, I guess you could simply make the
>>> clk_ops for the nkmp clocks public, and just re-implement set_rate
>>> using that logic.
>>
>> I would argue that this may be necessary for other PLL clocks too, if
>> you can get out of bounds output frequency, by changing the dividers too
>> early or too late. So perhaps this code should be generalized for other
>> PLL clocks too, instead.
> 
> The documentation says that only the CPU and DDR PLLs can be dynamically
> changed after boot.

The question is what exactly is meant by after boot. :) Anyway, if the
kernel has no business changing some other PLLs, if there's code for
changing them, should it be dropped?

regards,
  Ondrej



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