From: Ruxandra Ioana Radulescu <ruxandra.radulescu@nxp.com>
To: Dan Carpenter <dan.carpenter@oracle.com>
CC: "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
        "devel@driverdev.osuosl.org" <devel@driverdev.osuosl.org>,
        "arnd@arndb.de" <arnd@arndb.de>,
        "stuyoder@gmail.com" <stuyoder@gmail.com>,
        Roy Pledge <roy.pledge@nxp.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "agraf@suse.de" <agraf@suse.de>,
        "Bogdan Purcareata" <bogdan.purcareata@nxp.com>,
        Laurentiu Tudor <laurentiu.tudor@nxp.com>
Subject: RE: [PATCH] staging: fsl-mc/dpio: Fix incorrect comparison
Thread-Topic: [PATCH] staging: fsl-mc/dpio: Fix incorrect comparison
Thread-Index: AQHTN7oYgMCC9Nvla0+749/uaJzKTqLKQL4AgAAAVyA=
Date: Thu, 28 Sep 2017 13:07:48 +0000
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References: <20170927175728.3307-1-ruxandra.radulescu@nxp.com>
 <20170928124836.kdqjowqibab53hf5@mwanda>
In-Reply-To: <20170928124836.kdqjowqibab53hf5@mwanda>
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> -----Original Message-----
> From: Dan Carpenter [mailto:dan.carpenter@oracle.com]
> Sent: Thursday, September 28, 2017 3:49 PM
> To: Ruxandra Ioana Radulescu <ruxandra.radulescu@nxp.com>
> Cc: gregkh@linuxfoundation.org; devel@driverdev.osuosl.org;
> arnd@arndb.de; stuyoder@gmail.com; Roy Pledge <roy.pledge@nxp.com>;
> linux-kernel@vger.kernel.org; agraf@suse.de; Bogdan Purcareata
> <bogdan.purcareata@nxp.com>; Laurentiu Tudor
> <laurentiu.tudor@nxp.com>
> Subject: Re: [PATCH] staging: fsl-mc/dpio: Fix incorrect comparison
> 
> On Wed, Sep 27, 2017 at 12:57:28PM -0500, Ioana Radulescu wrote:
> > diff --git a/drivers/staging/fsl-mc/bus/dpio/dpio-service.c
> b/drivers/staging/fsl-mc/bus/dpio/dpio-service.c
> > index f809682..26922fc 100644
> > --- a/drivers/staging/fsl-mc/bus/dpio/dpio-service.c
> > +++ b/drivers/staging/fsl-mc/bus/dpio/dpio-service.c
> > @@ -76,7 +76,7 @@ static inline struct dpaa2_io
> *service_select_by_cpu(struct dpaa2_io *d,
> >  	if (d)
> >  		return d;
> >
> > -	if (unlikely(cpu >= num_possible_cpus()))
> > +	if (unlikely(cpu >= (int)num_possible_cpus()))
> 
> 
> Drivers shouldn't use likely/unlikley.
 
I was under the impression it's ok to use them on hotpath
(and while not entirely obvious, this function is called on
other drivers' hotpath).

> Please write it more explicitly like this:
> 
> 	if (cpu != -1 && cpu >= num_possible_cpus())
> 		return NULL;
> 
> Same for the other one as well.

Will rewrite as you suggested in the second email and send a v2.

Thanks,
Ioana