Re: [PATCH v4 2/7] units: Add HZ_PER_GHZ definition

Andy Shevchenko
2026-01-16T15:27:02Z

+Cc: Andi

On Fri, Jan 16, 2026 at 02:32:21PM +0000, Rodrigo Alencar via B4 Relay wrote:
>
> New PLL IIO driver supports output frequency of several GHz.
> The new define helps to constraint DT properties and frequency
> calculation parameters.

There is already pending patch to add this in I²C host controller subsystem.
On one hand the conflict, if any, is easy to resolve (the other patch adds
a couple of comments). On the other we are at almost rc6 and it seems DT people
are not happy about something, which would mean that the series most likely
will miss next merge window.

So, the solutions are:
- do nothing and resolve conflicts, if any
- define this constant locally in the respective IIO driver and drop it after merge
- postpone this series to the next cycle (effectively drop this patch)
- ask Andi to provide an immutable branch / tag with I²C host patches
- ask Andi to provide the only that patch in immutable tag / branch, but it
will require him to rebase his tree

I'm skeptical about last two options on the grounds on how the IIO works and
possible rebase requirement (which is not good to have).

I leave it to you and the respective maintainers to make a final decision.

> diff --git a/include/linux/units.h b/include/linux/units.h
> index 00e15de33eca..06870e9e90b8 100644
> --- a/include/linux/units.h
> +++ b/include/linux/units.h
> @@ -27,6 +27,7 @@
>
> #define HZ_PER_KHZ 1000UL
> #define HZ_PER_MHZ 1000000UL
> +#define HZ_PER_GHZ 1000000000UL
>
> #define KHZ_PER_MHZ 1000UL
> #define KHZ_PER_GHZ 1000000UL

--
With Best Regards,
Andy Shevchenko