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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        Jonathan Cameron <Jonathan.Cameron@huawei.com>,
        Matt Ranostay <matt.ranostay@konsulko.com>,
        Andy Shevchenko <andy.shevchenko@gmail.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.9 103/245] iio: prox: pulsed-light: Fix buffer alignment in iio_push_to_buffers_with_timestamp()
Date:   Mon, 19 Jul 2021 16:50:45 +0200
Message-Id: <20210719144943.752092403@linuxfoundation.org>
In-Reply-To: <20210719144940.288257948@linuxfoundation.org>
References: <20210719144940.288257948@linuxfoundation.org>
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From: Jonathan Cameron <Jonathan.Cameron@huawei.com>

[ Upstream commit 679cc377a03ff1944491eafc7355c1eb1fad4109 ]

To make code more readable, use a structure to express the channel
layout and ensure the timestamp is 8 byte aligned.

Found during an audit of all calls of uses of
iio_push_to_buffers_with_timestamp()

Fixes: cb119d535083 ("iio: proximity: add support for PulsedLight LIDAR")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Matt Ranostay <matt.ranostay@konsulko.com>
Acked-by: Matt Ranostay <matt.ranostay@konsulko.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20210501170121.512209-14-jic23@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/iio/proximity/pulsedlight-lidar-lite-v2.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/iio/proximity/pulsedlight-lidar-lite-v2.c b/drivers/iio/proximity/pulsedlight-lidar-lite-v2.c
index 46e969a3a9b7..ed7397f0b4c8 100644
--- a/drivers/iio/proximity/pulsedlight-lidar-lite-v2.c
+++ b/drivers/iio/proximity/pulsedlight-lidar-lite-v2.c
@@ -51,7 +51,11 @@ struct lidar_data {
 	int (*xfer)(struct lidar_data *data, u8 reg, u8 *val, int len);
 	int i2c_enabled;
 
-	u16 buffer[8]; /* 2 byte distance + 8 byte timestamp */
+	/* Ensure timestamp is naturally aligned */
+	struct {
+		u16 chan;
+		s64 timestamp __aligned(8);
+	} scan;
 };
 
 static const struct iio_chan_spec lidar_channels[] = {
@@ -236,9 +240,9 @@ static irqreturn_t lidar_trigger_handler(int irq, void *private)
 	struct lidar_data *data = iio_priv(indio_dev);
 	int ret;
 
-	ret = lidar_get_measurement(data, data->buffer);
+	ret = lidar_get_measurement(data, &data->scan.chan);
 	if (!ret) {
-		iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
+		iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
 						   iio_get_time_ns(indio_dev));
 	} else if (ret != -EINVAL) {
 		dev_err(&data->client->dev, "cannot read LIDAR measurement");
-- 
2.30.2