From d7a83bc38d8dd11b3df7e0db3739be6ced1667af Mon Sep 17 00:00:00 2001
From: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Date: Sun, 13 Jun 2021 16:10:39 +0100
Subject: [PATCH] iio: imu: adis16400: Fix buffer alignment requirements.
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Git-commit: d7a83bc38d8dd11b3df7e0db3739be6ced1667af
Patch-mainline: v5.16-rc1
References: git-fixes
iio_push_to_buffers_with_timestamp() requires that the buffer
is 8 byte alignment to ensure an inserted timestamp is naturally aligned.
This requirement was not met here when burst mode is in use beause
of a leading u16. Use the new iio_push_to_buffers_with_ts_unaligned()
function that has more relaxed requirements.
It is somewhat complex to access that actual data length, but a
safe bound can be found by using scan_bytes - sizeof(timestamp) so that
is used in this path.
More efficient approaches exist, but this ensure correctness at the
cost of using a bounce buffer.
Fixes: 5075e0720d93 ("iio: imu: adis: generalize burst mode support")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20210613151039.569883-5-jic23@kernel.org
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/iio/imu/adis16400.c | 20 +++++++++++++++-----
1 file changed, 15 insertions(+), 5 deletions(-)
diff --git a/drivers/iio/imu/adis16400.c b/drivers/iio/imu/adis16400.c
index b12917a7cb60..9fd30e62d6e8 100644
--- a/drivers/iio/imu/adis16400.c
+++ b/drivers/iio/imu/adis16400.c
@@ -641,13 +641,23 @@ static irqreturn_t adis16400_trigger_handler(int irq, void *p)
if (ret)
dev_err(&adis->spi->dev, "Failed to read data: %d\n", ret);
- if (st->variant->flags & ADIS16400_BURST_DIAG_STAT)
+ if (st->variant->flags & ADIS16400_BURST_DIAG_STAT) {
buffer = adis->buffer + sizeof(u16);
- else
- buffer = adis->buffer;
+ /*
+ * The size here is always larger than, or equal to the true
+ * size of the channel data. This may result in a larger copy
+ * than necessary, but as the target buffer will be
+ * buffer->scan_bytes this will be safe.
+ */
+ iio_push_to_buffers_with_ts_unaligned(indio_dev, buffer,
+ indio_dev->scan_bytes - sizeof(pf->timestamp),
+ pf->timestamp);
+ } else {
+ iio_push_to_buffers_with_timestamp(indio_dev,
+ adis->buffer,
+ pf->timestamp);
+ }
- iio_push_to_buffers_with_timestamp(indio_dev, buffer,
- pf->timestamp);
iio_trigger_notify_done(indio_dev->trig);
--
2.31.1