Re: [PATCH 0/2] iio: orientation: hid-sensor-rotation: fix quaternion alignment

[Andy Shevchenko <andriy.shevchenko@intel.com>]

On Mon, Feb 16, 2026 at 09:25:58AM -0600, David Lechner wrote:
> On 2/16/26 1:44 AM, Andy Shevchenko wrote:
> > On Sat, Feb 14, 2026 at 03:00:19PM -0600, David Lechner wrote:
> >> The main point of this series is to fix a regression reported in
> >> hid-sensor-rotation where the alignment of the quaternion field in the
> >> data was inadvertently changed from 16 bytes to 8 bytes. This is an
> >> unusually case (one of only 2 in the kernel) where the .repeat field of
> >> struct iio_scan_type is used and we have such a requirement. (The other
> >> case uses u16 instead of u32, so it wasn't affected.)
> >>
> >> To make the reason for the alignment more explicit to future readers,
> >> we introduce a new macro, IIO_DECLARE_REPEATED_ELEMENT, to declare the
> >> array with proper allignment. This is meant to follow the pattern of
> >> the similar IIO_DECLARE_BUFFER_WITH_TS() macro.
> > 
> > In both cases it's quaternion, maybe be more explicit and define
> > IIO_DECLARE_QUATERNION() ?
> 
> It is really the fact that the scan_type has .repeat > 1 that requires
> this, so I was trying to make a name that shows that link.
> 
> But right now, quaternion is the only thing that has .repeat > 1, so
> I guess it would be OK either way. We'll see if Jonathan has an
> opinion on the naming.

I think we should solve the problems when they appear. Naming explicitly
for quaternion makes it easier to get from the core reading without having
a variable name to repeat that. Magic 4  might not always be a quaternion.

Do we have "repeat" to be used in other cases, btw?

-- 
With Best Regards,
Andy Shevchenko