Re: [PATCH 1/5] iio: buffer: use permission specific variants of DEVICE_ATTR

[Joe Perches]

(Adding Greg KH who is I think the biggest proponent of these macros)

On Sat, 2018-01-06 at 12:35 +0000, Jonathan Cameron wrote:
> On Thu, 4 Jan 2018 20:07:14 +0530
> Aishwarya Pant <aishpant@xxxxxxxxx> wrote
> 
> > This is a clean-up patch which replaces DEVICE_ATTR macro with the file
> > permission specific DEVICE_ATTR_{RO/WO/RW} macros for compaction and
> > readability. Done using coccinelle.
> 
> Hmm. I'll be honest, I personally really dislike these macros.
> They absolutely don't help with readability because they obscure
> the connection between the attributes being created and their callbacks.
> Short is not the same as more readable.
> 
> Dropping off the prefixes from function names suddenly makes them
> appear a lot more generic than they are.  The only advantage is is
> standardizes their naming slightly - but that could be done whilst
> maintaining the more readable version that makes everything obvious.
> 
> I'll think on whether the compactness gains are sufficient to justify their
> use.
> 
> > 
> > Signed-off-by: Aishwarya Pant <aishpant@xxxxxxxxx>
> > ---
> >  drivers/iio/industrialio-buffer.c | 25 +++++++++++--------------
> >  1 file changed, 11 insertions(+), 14 deletions(-)
> > 
> > diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
> > index d2b465140a6b..ca565fbcff90 100644
> > --- a/drivers/iio/industrialio-buffer.c
> > +++ b/drivers/iio/industrialio-buffer.c
> > @@ -497,7 +497,7 @@ static int iio_buffer_add_channel_sysfs(struct iio_dev *indio_dev,
> >  	return ret;
> >  }
> >  
> > -static ssize_t iio_buffer_read_length(struct device *dev,
> > +static ssize_t length_show(struct device *dev,
> >  				      struct device_attribute *attr,
> >  				      char *buf)
> >  {
> > @@ -507,7 +507,7 @@ static ssize_t iio_buffer_read_length(struct device *dev,
> >  	return sprintf(buf, "%d\n", buffer->length);
> >  }
> >  
> > -static ssize_t iio_buffer_write_length(struct device *dev,
> > +static ssize_t length_store(struct device *dev,
> >  				       struct device_attribute *attr,
> >  				       const char *buf, size_t len)
> >  {
> > @@ -540,7 +540,7 @@ static ssize_t iio_buffer_write_length(struct device *dev,
> >  	return ret ? ret : len;
> >  }
> >  
> > -static ssize_t iio_buffer_show_enable(struct device *dev,
> > +static ssize_t enable_show(struct device *dev,
> >  				      struct device_attribute *attr,
> >  				      char *buf)
> >  {
> > @@ -1117,7 +1117,7 @@ void iio_disable_all_buffers(struct iio_dev *indio_dev)
> >  	iio_buffer_deactivate_all(indio_dev);
> >  }
> >  
> > -static ssize_t iio_buffer_store_enable(struct device *dev,
> > +static ssize_t enable_store(struct device *dev,
> >  				       struct device_attribute *attr,
> >  				       const char *buf,
> >  				       size_t len)
> > @@ -1153,7 +1153,7 @@ static ssize_t iio_buffer_store_enable(struct device *dev,
> >  
> >  static const char * const iio_scan_elements_group_name = "scan_elements";
> >  
> > -static ssize_t iio_buffer_show_watermark(struct device *dev,
> > +static ssize_t watermark_show(struct device *dev,
> >  					 struct device_attribute *attr,
> >  					 char *buf)
> >  {
> > @@ -1163,7 +1163,7 @@ static ssize_t iio_buffer_show_watermark(struct device *dev,
> >  	return sprintf(buf, "%u\n", buffer->watermark);
> >  }
> >  
> > -static ssize_t iio_buffer_store_watermark(struct device *dev,
> > +static ssize_t watermark_store(struct device *dev,
> >  					  struct device_attribute *attr,
> >  					  const char *buf,
> >  					  size_t len)
> > @@ -1198,16 +1198,13 @@ static ssize_t iio_buffer_store_watermark(struct device *dev,
> >  	return ret ? ret : len;
> >  }
> >  
> > -static DEVICE_ATTR(length, S_IRUGO | S_IWUSR, iio_buffer_read_length,
> > -		   iio_buffer_write_length);
> > +static DEVICE_ATTR_RW(length);
> >  static struct device_attribute dev_attr_length_ro = __ATTR(length,
> > -	S_IRUGO, iio_buffer_read_length, NULL);
> > -static DEVICE_ATTR(enable, S_IRUGO | S_IWUSR,
> > -		   iio_buffer_show_enable, iio_buffer_store_enable);
> > -static DEVICE_ATTR(watermark, S_IRUGO | S_IWUSR,
> > -		   iio_buffer_show_watermark, iio_buffer_store_watermark);
> > +	S_IRUGO, length_show, NULL);
> > +static DEVICE_ATTR_RW(enable);
> > +static DEVICE_ATTR_RW(watermark);
> >  static struct device_attribute dev_attr_watermark_ro = __ATTR(watermark,
> > -	S_IRUGO, iio_buffer_show_watermark, NULL);
> > +	S_IRUGO, watermark_show, NULL);
> >  
> >  static struct attribute *iio_buffer_attrs[] = {
> >  	&dev_attr_length.attr,
> 
>