Re: [PATCH 05/10] clkdev: add clkdev_create() helper

[Russell King - ARM Linux <linux@arm.linux.org.uk>]

On Mon, Mar 02, 2015 at 11:07:58AM -0800, Stephen Boyd wrote:
> On 03/02/15 09:06, Russell King wrote:
> > Add a helper to allocate and add a clk_lookup structure.  This can not
> > only be used in several places in clkdev.c to simplify the code, but
> > more importantly, can be used by callers of the clkdev code to simplify
> > their clkdev creation and registration.
> >
> > Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
> > ---
> >  drivers/clk/clkdev.c   | 52 ++++++++++++++++++++++++++++++++++++++------------
> >  include/linux/clkdev.h |  3 +++
> >  2 files changed, 43 insertions(+), 12 deletions(-)
> >
> > diff --git a/drivers/clk/clkdev.c b/drivers/clk/clkdev.c
> > index 043fd3633373..611b9acbad78 100644
> > --- a/drivers/clk/clkdev.c
> > +++ b/drivers/clk/clkdev.c
> > @@ -294,6 +294,19 @@ vclkdev_alloc(struct clk *clk, const char *con_id, const char *dev_fmt,
> >  	return &cla->cl;
> >  }
> >  
> > +static struct clk_lookup *
> > +vclkdev_create((struct clk *clk, const char *con_id, const char *dev_fmt,
> > +	va_list ap)
> > +{
> > +	struct clk_lookup *cl;
> > +
> > +	cl = vclkdev_alloc(clk, con_id, dev_fmt, ap);
> > +	if (cl)
> > +		clkdev_add(cl);
> > +
> > +	return cl;
> > +}
> > +
> >  struct clk_lookup * __init_refok
> >  clkdev_alloc(struct clk *clk, const char *con_id, const char *dev_fmt, ...)
> >  {
> > @@ -308,6 +321,28 @@ clkdev_alloc(struct clk *clk, const char *con_id, const char *dev_fmt, ...)
> >  }
> >  EXPORT_SYMBOL(clkdev_alloc);
> >  
> > +/**
> > + * clkdev_create - allocate and add a clkdev lookup structure
> > + * @clk: struct clk to associate with all clk_lookups
> > + * @con_id: connection ID string on device
> > + * @dev_fmt: format string describing device name
> > + *
> > + * Returns a clk_lookup structure, which can be later unregistered and
> > + * freed.
> 
> And returns NULL on failure? Any reason why we don't return an error
> pointer on failure?

Why should it when it's only error is "no memory" ?  It follows the
clkdev_alloc() and memory allocator pattern.

It'd also make the error handling in places like clk_add_alias() more
difficult (how that happened, I don't know...) though that could probably
be fixed as no one seems to bother checking the return value... maybe
that's a reason to make it return void ;)

-- 
FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up
according to speedtest.net.