Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.32 as permitted sender) client-ip=23.128.96.32;
Message-ID: <aa6270c5-46d7-4082-ab5a-9a850616b6fe@infradead.org>
Date:   Sun, 24 Sep 2023 21:25:29 -0700
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: ERR_PTR(0) in a couple of places
Content-Language: en-US
To:     Matthew Brost <matthew.brost@intel.com>,
        "Dr. David Alan Gilbert" <dave@treblig.org>
Cc:     mgreer@animalcreek.com, krzysztof.kozlowski@linaro.org,
        linux-kernel@vger.kernel.org, airlied@gmail.com,
        intel-gfx@lists.freedesktop.org
References: <ZQ+Fo9WKyGphwI8R@gallifrey>
 <ZREKJpfMx7ZEcw3n@DUT025-TGLU.fm.intel.com>
From:   Randy Dunlap <rdunlap@infradead.org>
In-Reply-To: <ZREKJpfMx7ZEcw3n@DUT025-TGLU.fm.intel.com>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Precedence: bulk


On 9/24/23 21:18, Matthew Brost wrote:
> On Sun, Sep 24, 2023 at 12:41:07AM +0000, Dr. David Alan Gilbert wrote:
>> Hi,
>>   I randomly noticed there are a couple of places in the kernel that
>> do
>>    ERR_PTR(0);
>>
>> and thought that was odd - shouldn't those just be NULL's ?
>>
>> 1) i915
>>   drivers/gpu/drm/i915/gt/uc/selftest_guc_multi_lrc.c : 47
>>
>>     if (i <= 1)
>>       return ERR_PTR(0);
> 
> Yes, s/ERR_PTR(0)/ERR_PTR(NULL)/
> 
> Matt

I agree with Dave's original suggestion since casting NULL isn't needed.

> 
>>
>>   from f9d72092cb490 
>>
>> 2) trf7970a
>>   drivers/nfc/trf7970a.c : 896
>>
>>       trf->ignore_timeout =
>>          !cancel_delayed_work(&trf->timeout_work);
>>       trf->rx_skb = ERR_PTR(0);
>>       trf7970a_send_upstream(trf);
>>
>>    from 1961843ceeca0
>>
>> Dave
>> -- 
>>  -----Open up your eyes, open up your mind, open up your code -------   
>> / Dr. David Alan Gilbert    |       Running GNU/Linux       | Happy  \ 
>> \        dave @ treblig.org |                               | In Hex /
>>  \ _________________________|_____ http://www.treblig.org   |_______/

-- 
~Randy