staging:iio: Fix scan mask update

When updating the scan mask we have to check the actual scan mask for if the
channel is already enabled, not the matching scan mask from the available
scan masks. The bit will already be set there and as a result the actual
scan mask will not get updated and the channel stays disabled.

Also fix the return value of iio_scan_el_store which would return 1 instead of
the number of bytes written if the channel was already active in the scan mask.

Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/staging/iio/industrialio-buffer.c b/drivers/staging/iio/industrialio-buffer.c
index b46ae6a2424f7dc079403b0e7018acaaa832bd4c..24c6aa4d82b9924963fa043e2f88ebc18240637a 100644 (file)
--- a/drivers/staging/iio/industrialio-buffer.c
+++ b/drivers/staging/iio/industrialio-buffer.c
@@ -174,7 +174,7 @@ static ssize_t iio_scan_el_store(struct device *dev,
 error_ret:
        mutex_unlock(&indio_dev->mlock);
 
-       return ret ? ret : len;
+       return ret < 0 ? ret : len;
 
 }
 
@@ -625,16 +625,8 @@ int iio_scan_mask_query(struct iio_buffer *buffer, int bit)
 
        if (!buffer->scan_mask)
                return 0;
-       if (indio_dev->available_scan_masks)
-               mask = iio_scan_mask_match(indio_dev->available_scan_masks,
-                                          indio_dev->masklength,
-                                          buffer->scan_mask);
-       else
-               mask = buffer->scan_mask;
-       if (!mask)
-               return 0;
 
-       return test_bit(bit, mask);
+       return test_bit(bit, buffer->scan_mask);
 };
 EXPORT_SYMBOL_GPL(iio_scan_mask_query);