diff mbox series

[06/15] iio: sx9310: Align memory

Message ID 20200728091057.6.I27a5605d9cb3ff643ef040c4ef932a30df9a8fac@changeid (mailing list archive)
State New
Headers show
Series sx9310 iio driver updates | expand

Commit Message

Daniel Campello July 28, 2020, 3:12 p.m. UTC
Use __aligned(8) to ensure that the timestamp is correctly aligned
when we call push_to_buffers

Signed-off-by: Daniel Campello <campello@chromium.org>
---

 drivers/iio/proximity/sx9310.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

Comments

Andy Shevchenko July 28, 2020, 6:11 p.m. UTC | #1
On Tue, Jul 28, 2020 at 6:15 PM Daniel Campello <campello@chromium.org> wrote:
>
> Use __aligned(8) to ensure that the timestamp is correctly aligned
> when we call push_to_buffers
>
> Signed-off-by: Daniel Campello <campello@chromium.org>
> ---
>
>  drivers/iio/proximity/sx9310.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/iio/proximity/sx9310.c b/drivers/iio/proximity/sx9310.c
> index de52afd7c13333..fb5c16f2aa6b1a 100644
> --- a/drivers/iio/proximity/sx9310.c
> +++ b/drivers/iio/proximity/sx9310.c
> @@ -131,8 +131,8 @@ struct sx9310_data {
>          */
>         bool prox_stat[SX9310_NUM_CHANNELS];
>         bool trigger_enabled;
> -       __be16 buffer[SX9310_NUM_CHANNELS +
> -                     4]; /* 64-bit data + 64-bit timestamp */
> +       /* 64-bit data + 64-bit timestamp buffer */
> +       __be16 buffer[SX9310_NUM_CHANNELS + 4] __aligned(8);

If the data amount (channels) is always the same, please, use struct approach.
Otherwise put a comment explaining dynamic data.
Daniel Campello July 28, 2020, 9:26 p.m. UTC | #2
On Tue, Jul 28, 2020 at 12:11 PM Andy Shevchenko
<andy.shevchenko@gmail.com> wrote:
>
> On Tue, Jul 28, 2020 at 6:15 PM Daniel Campello <campello@chromium.org> wrote:
> >
> > Use __aligned(8) to ensure that the timestamp is correctly aligned
> > when we call push_to_buffers
> >
> > Signed-off-by: Daniel Campello <campello@chromium.org>
> > ---
> >
> >  drivers/iio/proximity/sx9310.c | 6 +++---
> >  1 file changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/iio/proximity/sx9310.c b/drivers/iio/proximity/sx9310.c
> > index de52afd7c13333..fb5c16f2aa6b1a 100644
> > --- a/drivers/iio/proximity/sx9310.c
> > +++ b/drivers/iio/proximity/sx9310.c
> > @@ -131,8 +131,8 @@ struct sx9310_data {
> >          */
> >         bool prox_stat[SX9310_NUM_CHANNELS];
> >         bool trigger_enabled;
> > -       __be16 buffer[SX9310_NUM_CHANNELS +
> > -                     4]; /* 64-bit data + 64-bit timestamp */
> > +       /* 64-bit data + 64-bit timestamp buffer */
> > +       __be16 buffer[SX9310_NUM_CHANNELS + 4] __aligned(8);
>
> If the data amount (channels) is always the same, please, use struct approach.
> Otherwise put a comment explaining dynamic data.
I'm not sure what you mean here. I have a comment above for the size
of the array.
>
> --
> With Best Regards,
> Andy Shevchenko
Andy Shevchenko July 29, 2020, 6:52 a.m. UTC | #3
On Wed, Jul 29, 2020 at 12:26 AM Daniel Campello <campello@google.com> wrote:
> On Tue, Jul 28, 2020 at 12:11 PM Andy Shevchenko
> <andy.shevchenko@gmail.com> wrote:
> > On Tue, Jul 28, 2020 at 6:15 PM Daniel Campello <campello@chromium.org> wrote:

...

> > > -       __be16 buffer[SX9310_NUM_CHANNELS +
> > > -                     4]; /* 64-bit data + 64-bit timestamp */
> > > +       /* 64-bit data + 64-bit timestamp buffer */
> > > +       __be16 buffer[SX9310_NUM_CHANNELS + 4] __aligned(8);
> >
> > If the data amount (channels) is always the same, please, use struct approach.
> > Otherwise put a comment explaining dynamic data.
> I'm not sure what you mean here. I have a comment above for the size
> of the array.

Here [1] was a discussion about commenting on the dynamic amount of
data [see the cover letter and replies to it] in the buffer and the
struct approach [e.g. very first patch in the series].

[1]: https://lore.kernel.org/linux-iio/MN2PR12MB43905A2256F98BB5EFCE7DD3C4770@MN2PR12MB4390.namprd12.prod.outlook.com/T/
diff mbox series

Patch

diff --git a/drivers/iio/proximity/sx9310.c b/drivers/iio/proximity/sx9310.c
index de52afd7c13333..fb5c16f2aa6b1a 100644
--- a/drivers/iio/proximity/sx9310.c
+++ b/drivers/iio/proximity/sx9310.c
@@ -131,8 +131,8 @@  struct sx9310_data {
 	 */
 	bool prox_stat[SX9310_NUM_CHANNELS];
 	bool trigger_enabled;
-	__be16 buffer[SX9310_NUM_CHANNELS +
-		      4]; /* 64-bit data + 64-bit timestamp */
+	/* 64-bit data + 64-bit timestamp buffer */
+	__be16 buffer[SX9310_NUM_CHANNELS + 4] __aligned(8);
 	/* Remember enabled channels and sample rate during suspend. */
 	unsigned int suspend_ctrl0;
 	struct completion completion;
@@ -339,7 +339,7 @@  static int sx9310_read_prox_data(struct sx9310_data *data,
 	if (ret < 0)
 		return ret;
 
-	return regmap_bulk_read(data->regmap, chan->address, val, 2);
+	return regmap_bulk_read(data->regmap, chan->address, val, sizeof(*val));
 }
 
 /*