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From:   Steve deRosier <derosier@gmail.com>
Date:   Mon, 17 Aug 2020 21:40:42 -0700
Message-ID: <CALLGbRL95niReU+e1+5pO_byHdoWNuzBtHr_iz_HTAU0KwV2eg@mail.gmail.com>
Subject: Re: [PATCH] ath10k: fix the status check and wrong return
To:     Tang Bin <tangbin@cmss.chinamobile.com>
Cc:     Kalle Valo <kvalo@codeaurora.org>,
        "David S. Miller" <davem@davemloft.net>,
        Network Development <netdev@vger.kernel.org>,
        linux-wireless <linux-wireless@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>, ath10k@lists.infradead.org
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On Mon, Aug 17, 2020 at 6:43 PM Tang Bin <tangbin@cmss.chinamobile.com> wro=
te:
>
> Hi Kalle=EF=BC=9A
>
> =E5=9C=A8 2020/8/17 22:26, Kalle Valo =E5=86=99=E9=81=93:
> >> In the function ath10k_ahb_clock_init(), devm_clk_get() doesn't
> >> return NULL. Thus use IS_ERR() and PTR_ERR() to validate
> >> the returned value instead of IS_ERR_OR_NULL().
> > Why? What's the benefit of this patch? Or what harm does
> > IS_ERR_OR_NULL() create?
>
> Thanks for you reply, the benefit of this patch is simplify the code,
> because in
>
> this function, I don't think the situation of 'devm_clk_get() return
> NULL' exists.
>

I admit I'm not looking at HEAD, but at least in the two versions I've
got checked out, devm_clk_get() can theoretically return NULL. This
feels like a gratuitous change anyway, but in any case it's wrong and
could cause wrong behavior.

- Steve