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From: Jonathan Cameron <jic23@kernel.org>
To: linux-iio@vger.kernel.org,
	Andy Shevchenko <andy.shevchenko@gmail.com>,
	Nuno Sa <Nuno.Sa@analog.com>
Cc: Linus Walleij <linus.walleij@linaro.org>,
	Jan Kiszka <jan.kiszka@siemens.com>,
	Jonathan Cameron <Jonathan.Cameron@huawei.com>
Subject: [PATCH v2 3/4] iio: gyro: mpu3050: Fix alignment and size issues with buffers.
Date: Sun, 13 Jun 2021 16:10:38 +0100	[thread overview]
Message-ID: <20210613151039.569883-4-jic23@kernel.org> (raw)
In-Reply-To: <20210613151039.569883-1-jic23@kernel.org>

From: Jonathan Cameron <Jonathan.Cameron@huawei.com>

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: 3904b28efb2c ("iio: gyro: Add driver for the MPU-3050 gyroscope")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
---
 drivers/iio/gyro/mpu3050-core.c | 24 +++++++++++-------------
 1 file changed, 11 insertions(+), 13 deletions(-)

diff --git a/drivers/iio/gyro/mpu3050-core.c b/drivers/iio/gyro/mpu3050-core.c
index 3225de1f023b..ea387efab62d 100644
--- a/drivers/iio/gyro/mpu3050-core.c
+++ b/drivers/iio/gyro/mpu3050-core.c
@@ -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;
 
@@ -572,9 +569,10 @@ 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,
-							   &fifo_values[1],
-							   timestamp);
+			iio_push_to_buffers_with_ts_unaligned(indio_dev,
+							      &fifo_values[1],
+							      sizeof(__be16) * 4,
+							      timestamp);
 
 			fifocnt -= toread;
 			datums_from_fifo++;
@@ -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);
-- 
2.32.0


  parent reply	other threads:[~2021-06-13 15:08 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-13 15:10 [PATCH v2 0/4] IIO: Alignment fixes part 4 - bounce buffers for the hard cases Jonathan Cameron
2021-06-13 15:10 ` [PATCH v2 1/4] iio: core: Introduce iio_push_to_buffers_with_ts_unaligned() Jonathan Cameron
2021-06-14  8:33   ` Sa, Nuno
2021-06-13 15:10 ` [PATCH v2 2/4] iio: adc: ti-adc108s102: Fix alignment of buffer pushed to iio buffers Jonathan Cameron
2021-06-13 15:10 ` Jonathan Cameron [this message]
2021-06-13 15:10 ` [PATCH v2 4/4] iio: imu: adis16400: Fix buffer alignment requirements Jonathan Cameron
2021-06-14  8:25   ` Sa, Nuno
2021-07-18 14:55 ` [PATCH v2 0/4] IIO: Alignment fixes part 4 - bounce buffers for the hard cases Jonathan Cameron
2021-10-03 15:54   ` Jonathan Cameron

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