| From d3e6be28eb8b412c78065417ef21b82bffa63643 Mon Sep 17 00:00:00 2001 |
| From: =?UTF-8?q?Lars=20M=C3=B6llendorf?= <lars.moellendorf@plating.de> |
| Date: Fri, 13 Dec 2019 14:50:55 +0100 |
| Subject: [PATCH] iio: buffer: align the size of scan bytes to size of the |
| largest element |
| MIME-Version: 1.0 |
| Content-Type: text/plain; charset=UTF-8 |
| Content-Transfer-Encoding: 8bit |
| |
| commit 883f616530692d81cb70f8a32d85c0d2afc05f69 upstream. |
| |
| Previous versions of `iio_compute_scan_bytes` only aligned each element |
| to its own length (i.e. its own natural alignment). Because multiple |
| consecutive sets of scan elements are buffered this does not work in |
| case the computed scan bytes do not align with the natural alignment of |
| the first scan element in the set. |
| |
| This commit fixes this by aligning the scan bytes to the natural |
| alignment of the largest scan element in the set. |
| |
| Fixes: 959d2952d124 ("staging:iio: make iio_sw_buffer_preenable much more general.") |
| Signed-off-by: Lars Mรถllendorf <lars.moellendorf@plating.de> |
| Reviewed-by: Lars-Peter Clausen <lars@metafoo.de> |
| Cc: <Stable@vger.kernel.org> |
| Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> |
| |
| diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c |
| index c193d64e5217..112225c0e486 100644 |
| --- a/drivers/iio/industrialio-buffer.c |
| +++ b/drivers/iio/industrialio-buffer.c |
| @@ -566,7 +566,7 @@ static int iio_compute_scan_bytes(struct iio_dev *indio_dev, |
| const unsigned long *mask, bool timestamp) |
| { |
| unsigned bytes = 0; |
| - int length, i; |
| + int length, i, largest = 0; |
| |
| /* How much space will the demuxed element take? */ |
| for_each_set_bit(i, mask, |
| @@ -574,13 +574,17 @@ static int iio_compute_scan_bytes(struct iio_dev *indio_dev, |
| length = iio_storage_bytes_for_si(indio_dev, i); |
| bytes = ALIGN(bytes, length); |
| bytes += length; |
| + largest = max(largest, length); |
| } |
| |
| if (timestamp) { |
| length = iio_storage_bytes_for_timestamp(indio_dev); |
| bytes = ALIGN(bytes, length); |
| bytes += length; |
| + largest = max(largest, length); |
| } |
| + |
| + bytes = ALIGN(bytes, largest); |
| return bytes; |
| } |
| |
| -- |
| 2.7.4 |
| |