Re: [PATCH 3/3] staging: iio: ad5933: use iio_device_attach_kfifo_buffer() helper

[Ardelean, Alexandru]

On Sun, 2020-04-05 at 11:49 +0100, Jonathan Cameron wrote:
> [External]
> 
> On Wed, 1 Apr 2020 15:59:36 +0300
> Alexandru Ardelean <alexandru.ardelean@xxxxxxxxxx> wrote:
> 
> > This driver calls iio_kfifo_allocate() vs devm_iio_kfifo_allocate(). But
> > the conversion is still simpler here, and cleans-up/reduces some error
> > paths.
> > 
> > Signed-off-by: Alexandru Ardelean <alexandru.ardelean@xxxxxxxxxx>
> 
> This mixes devm managed stuff an unmanaged.  Hence it fails the 'obviously
> correct'
> test.  If you wanted to do this you'd first need to sort out the unmanaged
> bits to be automatically unwound (regulators and clocks). Or potentially
> reorder
> the driver so those happen after this allocation is done.
> 

Yeah.
I was a bit sloppy here.
I think tried a broader cleanup/rework would be a better idea here.


> Thanks,
> 
> Jonathan
> 
> > ---
> >  .../staging/iio/impedance-analyzer/ad5933.c   | 28 ++++---------------
> >  1 file changed, 5 insertions(+), 23 deletions(-)
> > 
> > diff --git a/drivers/staging/iio/impedance-analyzer/ad5933.c
> > b/drivers/staging/iio/impedance-analyzer/ad5933.c
> > index af0bcf95ee8a..7bde93c6dd74 100644
> > --- a/drivers/staging/iio/impedance-analyzer/ad5933.c
> > +++ b/drivers/staging/iio/impedance-analyzer/ad5933.c
> > @@ -602,22 +602,6 @@ static const struct iio_buffer_setup_ops
> > ad5933_ring_setup_ops = {
> >  	.postdisable = ad5933_ring_postdisable,
> >  };
> >  
> > -static int ad5933_register_ring_funcs_and_init(struct iio_dev *indio_dev)
> > -{
> > -	struct iio_buffer *buffer;
> > -
> > -	buffer = iio_kfifo_allocate();
> > -	if (!buffer)
> > -		return -ENOMEM;
> > -
> > -	iio_device_attach_buffer(indio_dev, buffer);
> > -
> > -	/* Ring buffer functions - here trigger setup related */
> > -	indio_dev->setup_ops = &ad5933_ring_setup_ops;
> > -
> > -	return 0;
> > -}
> > -
> >  static void ad5933_work(struct work_struct *work)
> >  {
> >  	struct ad5933_state *st = container_of(work,
> > @@ -738,26 +722,25 @@ static int ad5933_probe(struct i2c_client *client,
> >  	indio_dev->dev.parent = &client->dev;
> >  	indio_dev->info = &ad5933_info;
> >  	indio_dev->name = id->name;
> > -	indio_dev->modes = (INDIO_BUFFER_SOFTWARE | INDIO_DIRECT_MODE);
> > +	indio_dev->modes = INDIO_DIRECT_MODE;
> >  	indio_dev->channels = ad5933_channels;
> >  	indio_dev->num_channels = ARRAY_SIZE(ad5933_channels);
> >  
> > -	ret = ad5933_register_ring_funcs_and_init(indio_dev);
> > +	ret = iio_device_attach_kfifo_buffer(indio_dev, INDIO_BUFFER_SOFTWARE,
> > +					     &ad5933_ring_setup_ops);
> >  	if (ret)
> >  		goto error_disable_mclk;
> >  
> >  	ret = ad5933_setup(st);
> >  	if (ret)
> > -		goto error_unreg_ring;
> > +		goto error_disable_mclk;
> >  
> >  	ret = iio_device_register(indio_dev);
> >  	if (ret)
> > -		goto error_unreg_ring;
> > +		goto error_disable_mclk;
> >  
> >  	return 0;
> >  
> > -error_unreg_ring:
> > -	iio_kfifo_free(indio_dev->buffer);
> >  error_disable_mclk:
> >  	clk_disable_unprepare(st->mclk);
> >  error_disable_reg:
> > @@ -772,7 +755,6 @@ static int ad5933_remove(struct i2c_client *client)
> >  	struct ad5933_state *st = iio_priv(indio_dev);
> >  
> >  	iio_device_unregister(indio_dev);
> > -	iio_kfifo_free(indio_dev->buffer);
> >  	regulator_disable(st->reg);
> >  	clk_disable_unprepare(st->mclk);
> >