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Date:   Mon, 21 Sep 2020 13:24:25 +0200
From:   Thierry Reding <thierry.reding@gmail.com>
To:     Andy Shevchenko <andy.shevchenko@gmail.com>
Cc:     Dmitry Osipenko <digetx@gmail.com>,
        Jonathan Hunter <jonathanh@nvidia.com>,
        Laxman Dewangan <ldewangan@nvidia.com>,
        Wolfram Sang <wsa@the-dreams.de>,
        =?utf-8?B?TWljaGHFgiBNaXJvc8WCYXc=?= <mirq-linux@rere.qmqm.pl>,
        linux-i2c <linux-i2c@vger.kernel.org>,
        linux-tegra@vger.kernel.org,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v7 27/34] i2c: tegra: Check errors for both positive and
 negative values
Message-ID: <20200921112425.GK3950626@ulmo>
References: <20200908224006.25636-1-digetx@gmail.com>
 <20200908224006.25636-28-digetx@gmail.com>
 <20200917120955.GF3515672@ulmo>
 <CAHp75VdEoLAMvQWb1_p8ydROmY9p7KCqFGarRsgM8p8nDhyY7g@mail.gmail.com>
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On Thu, Sep 17, 2020 at 04:50:06PM +0300, Andy Shevchenko wrote:
> On Thu, Sep 17, 2020 at 3:09 PM Thierry Reding <thierry.reding@gmail.com>=
 wrote:
> > On Wed, Sep 09, 2020 at 01:39:59AM +0300, Dmitry Osipenko wrote:
>=20
> > Why? All of these functions "return 0 on success or a negative error
> > code on failure", don't they?
>=20
> And what is the point of having ' < 0' in all those cases?

It's explicitly checking for the documented error cases. And you'll
occasionally have a function that can return non-zero on success.
Testing for < 0 is the safest way to check for failure in the majority
of cases.

Thierry

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