Re: [PATCH] iio: querying buffer scan_mask should return 0/1

Alec Berg
2014-03-19T21:33:48Z

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I'm using x86, not sure what other architectures, if any, that it affects.

Thanks.

On Wed, Mar 19, 2014 at 1:31 PM, Jonathan Cameron <jic23@kernel.org> wrote:

>
>
> On March 19, 2014 6:50:44 PM GMT+00:00, Alec Berg <alecaberg@chromium.org>
> wrote:
> >Ensure that querying the IIO buffer scan_mask returns a value of
> >0 or 1. Currently querying the scan mask has the value returned
> >by test_bit(), which returns either true or false. For some
> >architectures test_bit() may return -1 for true, which will appear
> >to return an error when returning from iio_scan_mask_query().
> I'm curious now. Which architectures? Change is fine BTW. Will pick when
> I get a few mins...
> >
> >Additionally, it's important for the sysfs interface to consistently
> >return the same thing when querying the scan_mask.
> >
> >Signed-off-by: Alec Berg <alecaberg@chromium.org>
> >---
> > drivers/iio/industrialio-buffer.c | 6 ++++--
> > 1 file changed, 4 insertions(+), 2 deletions(-)
> >
> >diff --git a/drivers/iio/industrialio-buffer.c
> >b/drivers/iio/industrialio-buffer.c
> >index c67d83b..fe25042 100644
> >--- a/drivers/iio/industrialio-buffer.c
> >+++ b/drivers/iio/industrialio-buffer.c
> >@@ -165,7 +165,8 @@ static ssize_t iio_scan_el_show(struct device *dev,
> > int ret;
> > struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> >
> >- ret = test_bit(to_iio_dev_attr(attr)->address,
> >+ /* Ensure ret is 0 or 1. */
> >+ ret = !!test_bit(to_iio_dev_attr(attr)->address,
> > indio_dev->buffer->scan_mask);
> >
> > return sprintf(buf, "%d\n", ret);
> >@@ -866,7 +867,8 @@ int iio_scan_mask_query(struct iio_dev *indio_dev,
> > if (!buffer->scan_mask)
> > return 0;
> >
> >- return test_bit(bit, buffer->scan_mask);
> >+ /* Ensure return value is 0 or 1. */
> >+ return !!test_bit(bit, buffer->scan_mask);
> > };
> > EXPORT_SYMBOL_GPL(iio_scan_mask_query);
> >
>
> --
> Sent from my Android phone with K-9 Mail. Please excuse my brevity.
>

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