Re: [PATCH v2] docs: driver-api: device-io: Split out relaxed access mention
From: Jonathan Corbet
Date: Mon Mar 09 2026 - 12:21:35 EST
Andrew Davis <afd@xxxxxx> writes:
> We list all the normal non-relaxed device io functions first, but also
> list just the "read" versions of the relaxed device io functions.
> Instead of adding the "write" versions to that list, fix a statement
> below which should describe the relaxed versions so it is understood
> that both read and write have relaxed versions.
>
> Signed-off-by: Andrew Davis <afd@xxxxxx>
> ---
>
> Changes for v2:
> - None, rebase on v7.0-rc2 and resend
>
> Documentation/driver-api/device-io.rst | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/Documentation/driver-api/device-io.rst b/Documentation/driver-api/device-io.rst
> index d1aaa961cac4d..5b94973f44762 100644
> --- a/Documentation/driver-api/device-io.rst
> +++ b/Documentation/driver-api/device-io.rst
> @@ -56,7 +56,6 @@ Both read and write accesses are supported; there is no prefetch support
> at this time.
>
> The functions are named readb(), readw(), readl(), readq(),
> -readb_relaxed(), readw_relaxed(), readl_relaxed(), readq_relaxed(),
> writeb(), writew(), writel() and writeq().
>
> Some devices (such as framebuffers) would like to use larger transfers than
> @@ -67,7 +66,7 @@ guaranteed to copy data in order.
>
> The read and write functions are defined to be ordered. That is the
> compiler is not permitted to reorder the I/O sequence. When the ordering
> -can be compiler optimised, you can use __readb() and friends to
> +can be compiler optimised, you can use readb_relaxed() and friends to
> indicate the relaxed ordering. Use this with care.
...and we really think it's better to not just list the functions that
are available?
Among other things, the list would then automatically link to the
documentation for each function ... assuming, of course, that we ever
got around to documenting them...
Thanks,
jon