From: Jonathan Cameron <jic23@kernel.org>
To: linux-iio@vger.kernel.org
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>,
Stephan Gerhold <stephan@gerhold.net>,
Linus Walleij <linus.walleij@linaro.org>
Subject: Re: [PATCH 16/19] iio: magn: bmc150: Fix buffer alignment in iio_push_to_buffers_with_timestamp()
Date: Thu, 13 May 2021 18:50:46 +0100 [thread overview]
Message-ID: <20210513185046.1615083a@jic23-huawei> (raw)
In-Reply-To: <20210501170121.512209-17-jic23@kernel.org>
On Sat, 1 May 2021 18:01:18 +0100
Jonathan Cameron <jic23@kernel.org> wrote:
> From: Jonathan Cameron <Jonathan.Cameron@huawei.com>
>
> 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: c91746a2361d ("iio: magn: Add support for BMC150 magnetometer")
> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> Cc: Stephan Gerhold <stephan@gerhold.net>
> Cc: Linus Walleij <linus.walleij@linaro.org>
Applied, but with a tiny tweak to make this more obviously correct.
> ---
> drivers/iio/magnetometer/bmc150_magn.c | 11 +++++++----
> 1 file changed, 7 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/iio/magnetometer/bmc150_magn.c b/drivers/iio/magnetometer/bmc150_magn.c
> index 00f9766bad5c..dd5f80093a18 100644
> --- a/drivers/iio/magnetometer/bmc150_magn.c
> +++ b/drivers/iio/magnetometer/bmc150_magn.c
> @@ -138,8 +138,11 @@ struct bmc150_magn_data {
> struct regmap *regmap;
> struct regulator_bulk_data regulators[2];
> struct iio_mount_matrix orientation;
> - /* 4 x 32 bits for x, y z, 4 bytes align, 64 bits timestamp */
> - s32 buffer[6];
> + /* Ensure timestamp is naturally aligned */
> + struct {
> + s32 chans[4];
The whole point of the structure is to enforce the alignment without needing
to specify padding. There are only 3 actual chans, so I've reduced this to
s32 chans[3]
Result is exactly the same in practice, but it's more readable.
Thanks,
Jonathan
> + s64 timestamp __aligned(8);
> + } scan;
> struct iio_trigger *dready_trig;
> bool dready_trigger_on;
> int max_odr;
> @@ -675,11 +678,11 @@ static irqreturn_t bmc150_magn_trigger_handler(int irq, void *p)
> int ret;
>
> mutex_lock(&data->mutex);
> - ret = bmc150_magn_read_xyz(data, data->buffer);
> + ret = bmc150_magn_read_xyz(data, data->scan.chans);
> if (ret < 0)
> goto err;
>
> - iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
> + iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
> pf->timestamp);
>
> err:
next prev parent reply other threads:[~2021-05-13 17:49 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-01 17:01 [PATCH 00/19] IIO: Alignment fixes part 2 - struct used to ensure alignment Jonathan Cameron
2021-05-01 17:01 ` [PATCH 01/19] iio: accel: bma180: Fix buffer alignment in iio_push_to_buffers_with_timestamp() Jonathan Cameron
2021-05-13 17:22 ` Jonathan Cameron
2021-05-01 17:01 ` [PATCH 02/19] iio: accel: bma220: " Jonathan Cameron
2021-05-13 17:26 ` Jonathan Cameron
2021-05-01 17:01 ` [PATCH 03/19] iio: accel: hid: " Jonathan Cameron
2021-05-13 17:28 ` Jonathan Cameron
2021-05-01 17:01 ` [PATCH 04/19] iio: accel: kxcjk-1013: " Jonathan Cameron
2021-05-01 19:10 ` Andy Shevchenko
2021-05-13 17:33 ` Jonathan Cameron
2021-05-01 17:01 ` [PATCH 05/19] iio: accel: mxc4005: Fix overread of data and alignment issue Jonathan Cameron
2021-05-13 17:37 ` Jonathan Cameron
2021-05-01 17:01 ` [PATCH 06/19] iio: accel: stk8312: Fix buffer alignment in iio_push_to_buffers_with_timestamp() Jonathan Cameron
2021-05-13 17:39 ` Jonathan Cameron
2021-05-01 17:01 ` [PATCH 07/19] iio: accel: stk8ba50: " Jonathan Cameron
2021-05-01 17:01 ` [PATCH 08/19] iio: adc: ti-ads1015: " Jonathan Cameron
2021-05-01 17:01 ` [PATCH 09/19] iio: adc: vf610: " Jonathan Cameron
2021-05-01 17:01 ` [PATCH 10/19] iio: gyro: bmg160: " Jonathan Cameron
2021-05-01 17:01 ` [PATCH 11/19] iio: humidity: am2315: " Jonathan Cameron
2021-05-01 17:01 ` [PATCH 12/19] iio: prox: srf08: " Jonathan Cameron
2021-05-01 17:01 ` [PATCH 13/19] iio: prox: pulsed-light: " Jonathan Cameron
2021-05-06 6:46 ` Matt Ranostay
2021-05-01 17:01 ` [PATCH 14/19] iio: prox: as3935: " Jonathan Cameron
2021-05-06 6:45 ` Matt Ranostay
2021-05-01 17:01 ` [PATCH 15/19] iio: magn: hmc5843: " Jonathan Cameron
2021-05-01 17:01 ` [PATCH 16/19] iio: magn: bmc150: " Jonathan Cameron
2021-05-05 12:57 ` Linus Walleij
2021-05-07 9:23 ` Jonathan Cameron
2021-05-13 17:50 ` Jonathan Cameron [this message]
2021-05-01 17:01 ` [PATCH 17/19] iio: light: isl29125: " Jonathan Cameron
2021-05-01 17:01 ` [PATCH 18/19] iio: light: tcs3414: " Jonathan Cameron
2021-05-01 17:01 ` [PATCH 19/19] iio: light: tcs3472: " Jonathan Cameron
2021-05-01 19:09 ` Andy Shevchenko
2021-05-01 19:12 ` [PATCH 00/19] IIO: Alignment fixes part 2 - struct used to ensure alignment Andy Shevchenko
2021-05-13 17:54 ` Jonathan Cameron
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210513185046.1615083a@jic23-huawei \
--to=jic23@kernel.org \
--cc=Jonathan.Cameron@huawei.com \
--cc=linus.walleij@linaro.org \
--cc=linux-iio@vger.kernel.org \
--cc=stephan@gerhold.net \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).