iio: magn: hmc5843: Fix buffer alignment in iio_push_to_buffers_with_timestamp()

BugLink: https://bugs.launchpad.net/bugs/1938340
[ Upstream commit 1ef2f51e9fe424ccecca5bb0373d71b900c2cd41 ]

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: 7247645f6865 ("iio: hmc5843: Move hmc5843 out of staging")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20210501170121.512209-16-jic23@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

diff --git a/drivers/iio/magnetometer/hmc5843.h b/drivers/iio/magnetometer/hmc5843.h
index 3f6c0b6629415fa6794e53ac7dfb3bfa68ea9297..242f742f2643a67e696b67741188d33685adea7c 100644 (file)
--- a/drivers/iio/magnetometer/hmc5843.h
+++ b/drivers/iio/magnetometer/hmc5843.h
@@ -33,7 +33,8 @@ enum hmc5843_ids {
  * @lock:              update and read regmap data
  * @regmap:            hardware access register maps
  * @variant:           describe chip variants
- * @buffer:            3x 16-bit channels + padding + 64-bit timestamp
+ * @scan:              buffer to pack data for passing to
+ *                     iio_push_to_buffers_with_timestamp()
  */
 struct hmc5843_data {
        struct device *dev;
@@ -41,7 +42,10 @@ struct hmc5843_data {
        struct regmap *regmap;
        const struct hmc5843_chip_info *variant;
        struct iio_mount_matrix orientation;
-       __be16 buffer[8];
+       struct {
+               __be16 chans[3];
+               s64 timestamp __aligned(8);
+       } scan;
 };
 
 int hmc5843_common_probe(struct device *dev, struct regmap *regmap,

diff --git a/drivers/iio/magnetometer/hmc5843_core.c b/drivers/iio/magnetometer/hmc5843_core.c
index 780faea61d82ed7c0d78f906987e4f6bdac17fa3..221563e0c18fdd93c09f96afa7f6d50b6bfaed45 100644 (file)
--- a/drivers/iio/magnetometer/hmc5843_core.c
+++ b/drivers/iio/magnetometer/hmc5843_core.c
@@ -446,13 +446,13 @@ static irqreturn_t hmc5843_trigger_handler(int irq, void *p)
        }
 
        ret = regmap_bulk_read(data->regmap, HMC5843_DATA_OUT_MSB_REGS,
-                              data->buffer, 3 * sizeof(__be16));
+                              data->scan.chans, sizeof(data->scan.chans));
 
        mutex_unlock(&data->lock);
        if (ret < 0)
                goto done;
 
-       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));
 
 done: