From 2d44f11a4cc96599f8a0e3132872364745d07a8e Mon Sep 17 00:00:00 2001 From: =?utf8?q?Lars=20M=C3=B6llendorf?= 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=utf8 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 Möllendorf Reviewed-by: Lars-Peter Clausen Cc: Signed-off-by: Jonathan Cameron Signed-off-by: Greg Kroah-Hartman --- drivers/iio/industrialio-buffer.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c index c193d64..112225c 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