| Message ID | 20210501170121.512209-2-jic23@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | IIO: Alignment fixes part 2 - struct used to ensure alignment | expand |
On Sat, 1 May 2021 18:01:03 +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 this function. > > Fixes: b9a6a237ffc9 ("iio:bma180: Drop _update_scan_mode()") > Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> > Cc: Peter Meerwald <pmeerw@pmeerw.net> Applied to the togreg branch of iio.git with a minor fix. Note I'm taking these the slow way and nor marking them for stable as they've been there a very long time. > --- > drivers/iio/accel/bma180.c | 10 +++++++--- > 1 file changed, 7 insertions(+), 3 deletions(-) > > diff --git a/drivers/iio/accel/bma180.c b/drivers/iio/accel/bma180.c > index b8a7469cdae4..2e901f900ea7 100644 > --- a/drivers/iio/accel/bma180.c > +++ b/drivers/iio/accel/bma180.c > @@ -162,7 +162,11 @@ struct bma180_data { > int scale; > int bw; > bool pmode; > - u8 buff[16]; /* 3x 16-bit + 8-bit + padding + timestamp */ > + /* Ensure timestamp is naturally aligned */ > + struct { > + s16 chan[3]; The 8 bit in the comment above is misleading, but made me take another look at this. There are actually 4 channels on some devices, the last of which (temp) is 8 bits in a 16bit field. I changed this to be s16 chan[4] to reflect that. Thanks, Jonathan > + s64 timestamp __aligned(8); > + } scan; > }; > > enum bma180_chan { > @@ -938,12 +942,12 @@ static irqreturn_t bma180_trigger_handler(int irq, void *p) > mutex_unlock(&data->mutex); > goto err; > } > - ((s16 *)data->buff)[i++] = ret; > + data->scan.chan[i++] = ret; > } > > mutex_unlock(&data->mutex); > > - iio_push_to_buffers_with_timestamp(indio_dev, data->buff, time_ns); > + iio_push_to_buffers_with_timestamp(indio_dev, &data->scan, time_ns); > err: > iio_trigger_notify_done(indio_dev->trig); >
diff --git a/drivers/iio/accel/bma180.c b/drivers/iio/accel/bma180.c index b8a7469cdae4..2e901f900ea7 100644 --- a/drivers/iio/accel/bma180.c +++ b/drivers/iio/accel/bma180.c @@ -162,7 +162,11 @@ struct bma180_data { int scale; int bw; bool pmode; - u8 buff[16]; /* 3x 16-bit + 8-bit + padding + timestamp */ + /* Ensure timestamp is naturally aligned */ + struct { + s16 chan[3]; + s64 timestamp __aligned(8); + } scan; }; enum bma180_chan { @@ -938,12 +942,12 @@ static irqreturn_t bma180_trigger_handler(int irq, void *p) mutex_unlock(&data->mutex); goto err; } - ((s16 *)data->buff)[i++] = ret; + data->scan.chan[i++] = ret; } mutex_unlock(&data->mutex); - iio_push_to_buffers_with_timestamp(indio_dev, data->buff, time_ns); + iio_push_to_buffers_with_timestamp(indio_dev, &data->scan, time_ns); err: iio_trigger_notify_done(indio_dev->trig);