linux-kernel - Re: [PATCH] clk: add option to keep boot clocks on

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Message-ID: <20130427210735.GA9308@quad.lixom.net>
Date:	Sat, 27 Apr 2013 14:07:35 -0700
From:	Olof Johansson <olof@...om.net>
To:	Mike Turquette <mturquette@...aro.org>
Cc:	linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] clk: add option to keep boot clocks on

On Sat, Apr 27, 2013 at 11:17:13AM -0700, Mike Turquette wrote:
> Quoting Olof Johansson (2013-04-26 16:39:51)
> > This is primarily useful when there's a driver that doesn't claim clocks
> > properly, but the bootloader does. It's not expected to be used in normal
> > cases, but for bringup and debug it's very useful to have the option to
> > not gate unclaimed clocks that are still on.
> > 
> > Signed-off-by: Olof Johansson <olof@...om.net>
> > ---
> > 
> > Mike, this is a pretty trivial patch that I would love to see in 3.10
> > even though it's getting late. I'm definitely not picky about the naming
> > of the boot option, so feel free to change it.
> > 
> 
> This bike shed could be improved with a different color of paint.
> Opinions below:
> 
> > 
> > -Olof
> > 
> >  drivers/clk/clk.c | 14 ++++++++++++++
> >  1 file changed, 14 insertions(+)
> > 
> > diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
> > index 20ce67f..b22551e 100644
> > --- a/drivers/clk/clk.c
> > +++ b/drivers/clk/clk.c
> > @@ -499,10 +499,24 @@ out:
> >         return;
> >  }
> >  
> > +
> 
> Remove extra whitespace.
> 
> > +static bool keep_boot_clocks;
> > +static int __init clk_keep_boot_clocks(char *__unused)
> > +{
> > +       keep_boot_clocks = true;
> > +       return 1;
> > +}
> > +__setup("clk_keep_boot_clocks", clk_keep_boot_clocks);
> 
> s/clk_keep_boot_clocks/clk_ignore_unused/
> 
> This matches nicely with the existing CLK_IGNORE_UNUSED flag in
> include/linux/clk-provider.h
> 
> In addition to Randy's suggestion to update kernel-parameters.txt,
> please also toss in a note somewhere in Documentation/clk.txt so that
> others bringing up new platforms can more easily find out about this
> boot option.  Don't worry about making it pretty since I plan to rework
> the clock documentation for 3.11.
> 
> Otherwise patch looks good to me.  I did some testing and I would be
> comfortable sneaking this in for 3.10.

Great, thanks. I'm happy to paint in any color requested. :)

V2 patch posted separately.


-Olof
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