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Message-ID: <46299274-d827-279f-cadf-020e93296c13@hust.edu.cn>
Date:   Mon, 24 Apr 2023 20:03:42 +0800
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Subject: Re: [PATCH] spi: davinci: Remove dead code in `davinci_spi_probe()`
To:     Mark Brown <broonie@kernel.org>, Li Ningke <lnk_01@hust.edu.cn>
Cc:     hust-os-kernel-patches@googlegroups.com, linux-spi@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <20230423032446.34347-1-lnk_01@hust.edu.cn>
 <d29c4b3e-9e82-4ea9-9f0c-a8e2c7637eb9@sirena.org.uk>
From:   Dongliang Mu <dzm91@hust.edu.cn>
In-Reply-To: <d29c4b3e-9e82-4ea9-9f0c-a8e2c7637eb9@sirena.org.uk>
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On 2023/4/24 19:48, Mark Brown wrote:
> On Sun, Apr 23, 2023 at 03:24:46AM +0000, Li Ningke wrote:
>> Smatch complains that
>> drivers/spi/spi-davinci.c:915 davinci_spi_probe() warn:
>> platform_get_irq() does not return zero
>>
>> There is no need to check whether the return value is zero as
>> `platform_get_irq()` only returns non-zero IRQ number on success
>> or negative error number on failure, removing them to solve this
>> problem.
> Is that check valid?  0 was a valid interrupt for some architectures...

We just follow the comments of platform_get_irq().

/**
  * platform_get_irq - get an IRQ for a device
  * @dev: platform device
  * @num: IRQ number index
  *
  * Gets an IRQ for a platform device and prints an error message if 
finding the
  * IRQ fails. Device drivers should check the return value for errors 
so as to
  * not pass a negative integer value to the request_irq() APIs.
  *
  * For example::
  *
  *              int irq = platform_get_irq(pdev, 0);
  *              if (irq < 0)
  *                      return irq;
  *
  * Return: non-zero IRQ number on success, negative error number on 
failure.
  */
int platform_get_irq(struct platform_device *dev, unsigned int num)
{
         int ret;

         ret = platform_get_irq_optional(dev, num);
         if (ret < 0)
                 return dev_err_probe(&dev->dev, ret,
                                      "IRQ index %u not found\n", num);

         return ret;
}