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Subject: Re: [PATCH -next] mtd: docg3: Fix passing zero to 'PTR_ERR' warning
 in doc_probe_device
To:     Boris Brezillon <bbrezillon@kernel.org>
References: <20190123065827.16748-1-yuehaibing@huawei.com>
 <20190123101253.243add9d@bbrezillon>
CC:     <robert.jarzmik@free.fr>, <dwmw2@infradead.org>,
        <computersforpeace@gmail.com>, <marek.vasut@gmail.com>,
        <richard@nod.at>, <linux-kernel@vger.kernel.org>,
        <linux-mtd@lists.infradead.org>
From:   YueHaibing <yuehaibing@huawei.com>
Message-ID: <86533285-e800-5cc0-f495-88fff8326b5a@huawei.com>
Date:   Wed, 23 Jan 2019 17:43:58 +0800
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On 2019/1/23 17:12, Boris Brezillon wrote:
> On Wed, 23 Jan 2019 14:58:27 +0800
> YueHaibing <yuehaibing@huawei.com> wrote:
> 
>> Fix a static code checker warning:
>> drivers/mtd/devices/docg3.c:1875
>>  doc_probe_device() warn: passing zero to 'ERR_PTR'
>>
>> Fixes: ae9d4934b2d7 ("mtd: docg3: add multiple floor support")
>> Signed-off-by: YueHaibing <yuehaibing@huawei.com>
>> ---
>>  drivers/mtd/devices/docg3.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/mtd/devices/docg3.c b/drivers/mtd/devices/docg3.c
>> index 4c94fc0..60ddc38 100644
>> --- a/drivers/mtd/devices/docg3.c
>> +++ b/drivers/mtd/devices/docg3.c
>> @@ -1872,7 +1872,7 @@ doc_probe_device(struct docg3_cascade *cascade, int floor, struct device *dev)
>>  nomem2:
>>  	kfree(docg3);
>>  nomem1:
>> -	return ERR_PTR(ret);
>> +	return ret ? ERR_PTR(ret) : NULL;
>>  }
>>  
> 
> This is not the right fix, you should instead set ret to -EINVAL:

Thanks , will fix it in v2.

And seems doc_probe_device cannot return NULL. The NULL check of doc_probe_device
in docg3_probe also can been removed, right?

> 
> --->8---
> diff --git a/drivers/mtd/devices/docg3.c b/drivers/mtd/devices/docg3.c
> index 4c94fc096696..6b84db411232 100644
> --- a/drivers/mtd/devices/docg3.c
> +++ b/drivers/mtd/devices/docg3.c
> @@ -1842,7 +1842,7 @@ doc_probe_device(struct docg3_cascade *cascade, int floor, struct device *dev)
>         chip_id = doc_register_readw(docg3, DOC_CHIPID);
>         chip_id_inv = doc_register_readw(docg3, DOC_CHIPID_INV);
>  
> -       ret = 0;
> +       ret = -ENOMEM;
>         if (chip_id != (u16)(~chip_id_inv)) {
>                 goto nomem4;
>         }
> 
> .
>