Subject: Re: [PATCH] ptp: ixp46x: Fix error handling in ptp_ixp_probe()
To:     Linus Walleij <linus.walleij@linaro.org>
Cc:     davem@davemloft.net, kuba@kernel.org, arnd@arndb.de,
        wanjiabing@vivo.com, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <20211126011039.32-1-tangbin@cmss.chinamobile.com>
 <CACRpkdayKYeizBt=dspQ2VdsQvpc8iq7XeaT7SnRiCyMVO2Bsw@mail.gmail.com>
From:   tangbin <tangbin@cmss.chinamobile.com>
Message-ID: <53308403-a6b1-3af4-27ff-9e772e378bd2@cmss.chinamobile.com>
Date:   Fri, 26 Nov 2021 09:39:07 +0800
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Hi

On 2021/11/26 9:26, Linus Walleij wrote:
> On Fri, Nov 26, 2021 at 2:10 AM Tang Bin <tangbin@cmss.chinamobile.com> wrote:
>
>> In the function ptp_ixp_probe(), when get irq failed
>> after executing platform_get_irq(), the negative value
>> returned will not be detected here. So fix error handling
>> in this place.
>>
>> Fixes: 9055a2f591629 ("ixp4xx_eth: make ptp support a platform driver")
>> Signed-off-by: Tang Bin <tangbin@cmss.chinamobile.com>
> OK the intention is right but:
>
>> -           !ixp_clock.master_irq || !ixp_clock.slave_irq)
>> +           (ixp_clock.master_irq < 0) || (ixp_clock.slave_irq < 0))
> Keep disallowing 0. Because that is not a valid IRQ.
>
> ... <= 0 ...

Please look at the function platform_get_irq() in the file 
drivers/base/platform.c,

the example is :

     * int irq = platform_get_irq(pdev, 0);

     * if (irq < 0)

     *        return irq;

Thanks

Tang Bin