[PATCH 4.19 200/421] iio: adc: mxs-lradc: Fix buffer alignment in iio_push_to_buffers_with_timestamp()

[Greg Kroah-Hartman]

From: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>

[ Upstream commit 6a6be221b8bd561b053f0701ec752a5ed9007f69 ]

To make code more readable, use a structure to express the channel
layout and ensure the timestamp is 8 byte aligned.
Add a comment on why the buffer is the size it is as not immediately
obvious.

Found during an audit of all calls of this function.

Fixes: 6dd112b9f85e ("iio: adc: mxs-lradc: Add support for ADC driver")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Cc: Andreas Klinger <ak@xxxxxxxxxxxxx>
Reviewed-by: Nuno Sá <nuno.sa@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20210613152301.571002-4-jic23@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/iio/adc/mxs-lradc-adc.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/iio/adc/mxs-lradc-adc.c b/drivers/iio/adc/mxs-lradc-adc.c
index c627513d9f0f..fc8b70d8d64c 100644
--- a/drivers/iio/adc/mxs-lradc-adc.c
+++ b/drivers/iio/adc/mxs-lradc-adc.c
@@ -124,7 +124,8 @@ struct mxs_lradc_adc {
 	struct device		*dev;
 
 	void __iomem		*base;
-	u32			buffer[10];
+	/* Maximum of 8 channels + 8 byte ts */
+	u32			buffer[10] __aligned(8);
 	struct iio_trigger	*trig;
 	struct completion	completion;
 	spinlock_t		lock;
-- 
2.30.2