linux-kernel - Re: [PATCH V2 1/6] PM / OPP: Free resources and properly return error on failure

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Date:	Tue, 11 Aug 2015 20:29:38 +0530
From:	Viresh Kumar <viresh.kumar@...aro.org>
To:	Dan Carpenter <dan.carpenter@...cle.com>
Cc:	Rafael Wysocki <rjw@...ysocki.net>, nm@...com,
	sboyd@...eaurora.org, linaro-kernel@...ts.linaro.org,
	linux-pm@...r.kernel.org, khilman@...aro.org,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Len Brown <len.brown@...el.com>,
	open list <linux-kernel@...r.kernel.org>,
	Pavel Machek <pavel@....cz>
Subject: Re: [PATCH V2 1/6] PM / OPP: Free resources and properly return
 error on failure

On 11-08-15, 17:43, Dan Carpenter wrote:
> > @@ -1323,28 +1323,29 @@ static int _of_init_opp_table_v2(struct device *dev,
> >  		if (ret) {
> >  			dev_err(dev, "%s: Failed to add OPP, %d\n", __func__,
> >  				ret);
> > -			break;
> > +			goto free_table;
> >  		}
> >  	}
> >  
> >  	/* There should be one of more OPP defined */
> > -	if (WARN_ON(!count))
> > +	if (WARN_ON(!count)) {
> > +		ret = -ENOENT;
> >  		goto put_opp_np;
> > +	}

The purpose of 'count' here is to see if the dtb contained any OPP
nodes or not. i.e. if we ever entered the body of
for_each_available_child_of_node() or not..

Its different than, "if we were able to add any OPPs";

> This is weird to me, because we are going backwards.  What happens if
> we goto free_table without adding anything?

It will WARN() today.

> I suspect it's fine, but if
> it's a bug then this code still has problems.

I don't think we have a bug here, we never added anything and so don't
need to free it.

> What about if we only increment count when _opp_add_static_v2()
> succeeds

That's not what we want.

-- 
viresh
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