Re: [PATCH 5/7] iio: core: simplify some devm functions

From: Yicong Yang <yangyicong@hisilicon.com>
To: Alexandru Ardelean <ardeleanalex@gmail.com>
Cc: Jonathan Cameron <jic23@kernel.org>,
	linux-iio <linux-iio@vger.kernel.org>,
	Lars-Peter Clausen <lars@metafoo.de>,
	"Hennerich, Michael" <Michael.Hennerich@analog.com>,
	Peter Meerwald-Stadler <pmeerw@pmeerw.net>,
	<prime.zeng@huawei.com>, Tian Tao <tiantao6@hisilicon.com>
Subject: Re: [PATCH 5/7] iio: core: simplify some devm functions
Date: Fri, 9 Apr 2021 15:21:53 +0800	[thread overview]
Message-ID: <9f1257a2-a69e-acbc-8c0a-2d2157274225@hisilicon.com> (raw)
In-Reply-To: <CA+U=DspZCGVjFxB0YH7OAPBKhFAKz=a9Q=O7xW-Xu4BPZKC=pA@mail.gmail.com>

On 2021/4/8 21:09, Alexandru Ardelean wrote:
> On Thu, Apr 8, 2021 at 2:41 PM Yicong Yang <yangyicong@hisilicon.com> wrote:
>>
>> Use devm_add_action_or_reset() instead of devres_alloc() and
>> devres_add(), which works the same. This will simplify the
>> code. There is no functional changes.
>>
>> Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
>> ---
>>  drivers/iio/industrialio-core.c | 43 +++++++++++++++--------------------------
>>  1 file changed, 16 insertions(+), 27 deletions(-)
>>
>> diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
>> index 7db761a..2dfbed3 100644
>> --- a/drivers/iio/industrialio-core.c
>> +++ b/drivers/iio/industrialio-core.c
>> @@ -1627,9 +1627,9 @@ void iio_device_free(struct iio_dev *dev)
>>  }
>>  EXPORT_SYMBOL(iio_device_free);
>>
>> -static void devm_iio_device_release(struct device *dev, void *res)
>> +static void devm_iio_device_release(void *iio_dev)
>>  {
>> -       iio_device_free(*(struct iio_dev **)res);
>> +       iio_device_free(iio_dev);
>>  }
>>
>>  /**
>> @@ -1645,20 +1645,17 @@ static void devm_iio_device_release(struct device *dev, void *res)
>>   */
>>  struct iio_dev *devm_iio_device_alloc(struct device *parent, int sizeof_priv)
>>  {
>> -       struct iio_dev **ptr, *iio_dev;
>> -
>> -       ptr = devres_alloc(devm_iio_device_release, sizeof(*ptr),
>> -                          GFP_KERNEL);
>> -       if (!ptr)
>> -               return NULL;
>> +       struct iio_dev *iio_dev;
>> +       int ret;
>>
>>         iio_dev = iio_device_alloc(parent, sizeof_priv);
>> -       if (iio_dev) {
>> -               *ptr = iio_dev;
>> -               devres_add(parent, ptr);
>> -       } else {
>> -               devres_free(ptr);
>> -       }
>> +       if (!iio_dev)
>> +               return iio_dev;
> 
> This is correct.
> But the preference is usually:
>         if (!iio_dev)
>             return NULL;
> 

since it returned iio_dev when failure before, so i just keep as is

>> +
>> +       ret = devm_add_action_or_reset(parent, devm_iio_device_release,
>> +                                      iio_dev);
>> +       if (ret)
>> +               return ERR_PTR(ret);
>>
>>         return iio_dev;
>>  }
>> @@ -1889,29 +1886,21 @@ void iio_device_unregister(struct iio_dev *indio_dev)
>>  }
>>  EXPORT_SYMBOL(iio_device_unregister);
>>
>> -static void devm_iio_device_unreg(struct device *dev, void *res)
>> +static void devm_iio_device_unreg(void *indio_dev)
>>  {
>> -       iio_device_unregister(*(struct iio_dev **)res);
>> +       iio_device_unregister(indio_dev);
>>  }
>>
>>  int __devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev,
>>                                struct module *this_mod)
>>  {
>> -       struct iio_dev **ptr;
>>         int ret;
>>
>> -       ptr = devres_alloc(devm_iio_device_unreg, sizeof(*ptr), GFP_KERNEL);
>> -       if (!ptr)
>> -               return -ENOMEM;
>> -
>> -       *ptr = indio_dev;
>>         ret = __iio_device_register(indio_dev, this_mod);
>> -       if (!ret)
>> -               devres_add(dev, ptr);
>> -       else
>> -               devres_free(ptr);
>> +       if (ret)
>> +               return ret;
>>
>> -       return ret;
>> +       return devm_add_action_or_reset(dev, devm_iio_device_unreg, indio_dev);
>>  }
>>  EXPORT_SYMBOL_GPL(__devm_iio_device_register);
>>
>> --
>> 2.8.1
>>
> 
> .
>