Commit b5ca2046 authored by Jonathan Cameron's avatar Jonathan Cameron
Browse files

iio: gyro: mpu3050: Fix alignment and size issues with buffers. 



Fix a set of closely related issues.
1. When using fifo_values() there was not enough space for the timestamp to
   be inserted by iio_push_to_buffers_with_timestamp()
2. fifo_values() did not meet the alignment requirement of
   iio_push_to_buffers_with_timestamp()
3. hw_values did not meet the alignment requirement either.

1 and 2 fixed by using new iio_push_to_buffers_with_ts_unaligned() which has
no alignment or space padding requirements.
3 fixed by introducing a structure that makes the space and alignment
requirements explicit.

Fixes: 3904b28e ("iio: gyro: Add driver for the MPU-3050 gyroscope")
Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20210613151039.569883-4-jic23@kernel.org
parent cbe5c697

drivers/iio/gyro/mpu3050-core.c

+11 −13
Original line number Diff line number Diff line
@@ -471,13 +471,10 @@ static irqreturn_t mpu3050_trigger_handler(int irq, void *p) 
	struct iio_dev *indio_dev = pf->indio_dev;

	struct mpu3050 *mpu3050 = iio_priv(indio_dev);

	int ret;

	/*

	 * Temperature 1*16 bits

	 * Three axes 3*16 bits

	 * Timestamp 64 bits (4*16 bits)

	 * Sum total 8*16 bits

	 */

	__be16 hw_values[8];

	struct {

		__be16 chans[4];

		s64 timestamp __aligned(8);

	} scan;

	s64 timestamp;

	unsigned int datums_from_fifo = 0;
@@ -572,8 +569,9 @@ static irqreturn_t mpu3050_trigger_handler(int irq, void *p) 
				fifo_values[4]);



			/* Index past the footer (fifo_values[0]) and push */

			iio_push_to_buffers_with_timestamp(indio_dev,

			iio_push_to_buffers_with_ts_unaligned(indio_dev,

							      &fifo_values[1],

							      sizeof(__be16) * 4,

							      timestamp);



			fifocnt -= toread;
@@ -632,15 +630,15 @@ static irqreturn_t mpu3050_trigger_handler(int irq, void *p) 
		goto out_trigger_unlock;

	}



	ret = regmap_bulk_read(mpu3050->map, MPU3050_TEMP_H, &hw_values,

			       sizeof(hw_values));

	ret = regmap_bulk_read(mpu3050->map, MPU3050_TEMP_H, scan.chans,

			       sizeof(scan.chans));

	if (ret) {

		dev_err(mpu3050->dev,

			"error reading axis data\n");

		goto out_trigger_unlock;

	}



	iio_push_to_buffers_with_timestamp(indio_dev, hw_values, timestamp);

	iio_push_to_buffers_with_timestamp(indio_dev, &scan, timestamp);



out_trigger_unlock:

	mutex_unlock(&mpu3050->lock);