iio: buffer: check return value of iio_compute_scan_bytes()

Check return value of iio_compute_scan_bytes() as it can return an
error.

The result is moved to an output parameter while we are touching this
as we will need to add a second output parameter in a later change.

The return type of iio_buffer_update_bytes_per_datum() also had to be
changed to propagate the error.

Signed-off-by: David Lechner <dlechner@baylibre.com>
Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
index 46f36a6ed2710ab611202734ed0f112789559770..71dfc81cb9e57c3bab543e526faa5050dbc5adeb 100644 (file)
--- a/drivers/iio/industrialio-buffer.c
+++ b/drivers/iio/industrialio-buffer.c
@@ -764,7 +764,8 @@ static int iio_storage_bytes_for_timestamp(struct iio_dev *indio_dev)
 }
 
 static int iio_compute_scan_bytes(struct iio_dev *indio_dev,
-                                 const unsigned long *mask, bool timestamp)
+                                 const unsigned long *mask, bool timestamp,
+                                 unsigned int *scan_bytes)
 {
        unsigned int bytes = 0;
        int length, i, largest = 0;
@@ -790,8 +791,9 @@ static int iio_compute_scan_bytes(struct iio_dev *indio_dev,
                largest = max(largest, length);
        }
 
-       bytes = ALIGN(bytes, largest);
-       return bytes;
+       *scan_bytes = ALIGN(bytes, largest);
+
+       return 0;
 }
 
 static void iio_buffer_activate(struct iio_dev *indio_dev,
@@ -836,18 +838,23 @@ static int iio_buffer_disable(struct iio_buffer *buffer,
        return buffer->access->disable(buffer, indio_dev);
 }
 
-static void iio_buffer_update_bytes_per_datum(struct iio_dev *indio_dev,
-                                             struct iio_buffer *buffer)
+static int iio_buffer_update_bytes_per_datum(struct iio_dev *indio_dev,
+                                            struct iio_buffer *buffer)
 {
        unsigned int bytes;
+       int ret;
 
        if (!buffer->access->set_bytes_per_datum)
-               return;
+               return 0;
 
-       bytes = iio_compute_scan_bytes(indio_dev, buffer->scan_mask,
-                                      buffer->scan_timestamp);
+       ret = iio_compute_scan_bytes(indio_dev, buffer->scan_mask,
+                                    buffer->scan_timestamp, &bytes);
+       if (ret)
+               return ret;
 
        buffer->access->set_bytes_per_datum(buffer, bytes);
+
+       return 0;
 }
 
 static int iio_buffer_request_update(struct iio_dev *indio_dev,
@@ -855,7 +862,10 @@ static int iio_buffer_request_update(struct iio_dev *indio_dev,
 {
        int ret;
 
-       iio_buffer_update_bytes_per_datum(indio_dev, buffer);
+       ret = iio_buffer_update_bytes_per_datum(indio_dev, buffer);
+       if (ret)
+               return ret;
+
        if (buffer->access->request_update) {
                ret = buffer->access->request_update(buffer);
                if (ret) {
@@ -898,6 +908,7 @@ static int iio_verify_update(struct iio_dev *indio_dev,
        struct iio_buffer *buffer;
        bool scan_timestamp;
        unsigned int modes;
+       int ret;
 
        if (insert_buffer &&
            bitmap_empty(insert_buffer->scan_mask, masklength)) {
@@ -985,8 +996,11 @@ static int iio_verify_update(struct iio_dev *indio_dev,
                scan_mask = compound_mask;
        }
 
-       config->scan_bytes = iio_compute_scan_bytes(indio_dev,
-                                                   scan_mask, scan_timestamp);
+       ret = iio_compute_scan_bytes(indio_dev, scan_mask, scan_timestamp,
+                                    &config->scan_bytes);
+       if (ret)
+               return ret;
+
        config->scan_mask = scan_mask;
        config->scan_timestamp = scan_timestamp;