Re: [PATCH] Docs/driver-api/uio-howto: document mmap_prepare callback

From: Lorenzo Stoakes

Date: Tue Jun 23 2026 - 12:48:52 EST


On Mon, Jun 22, 2026 at 06:18:21PM +0000, Doehyun Baek wrote:
> The UIO howto still documents an mmap callback in struct uio_info.
> That field was replaced by mmap_prepare, which takes a struct
> vm_area_desc.
>
> A UIO driver following the current howto no longer builds because
> struct uio_info has no mmap member. Update the documented callback
> signature and matching text to match the current API.
>
> Fixes: 933f05f58ac6 ("uio: replace deprecated mmap hook with mmap_prepare in uio_info")
> Signed-off-by: Doehyun Baek <doehyunbaek@xxxxxxxxx>

Ah thanks apologies for missing this! LGTM so:

Reviewed-by: Lorenzo Stoakes <ljs@xxxxxxxxxx>

> ---
> Documentation/driver-api/uio-howto.rst | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/driver-api/uio-howto.rst b/Documentation/driver-api/uio-howto.rst
> index 907ffa3b38f5..c08472dfbcfe 100644
> --- a/Documentation/driver-api/uio-howto.rst
> +++ b/Documentation/driver-api/uio-howto.rst
> @@ -246,10 +246,10 @@ the members are required, others are optional.
> hardware interrupt number. The flags given here will be used in the
> call to :c:func:`request_irq()`.
>
> -- ``int (*mmap)(struct uio_info *info, struct vm_area_struct *vma)``:
> +- ``int (*mmap_prepare)(struct uio_info *info, struct vm_area_desc *desc)``:
> Optional. If you need a special :c:func:`mmap()`
> function, you can set it here. If this pointer is not NULL, your
> - :c:func:`mmap()` will be called instead of the built-in one.
> + ``mmap_prepare`` will be called instead of the built-in one.
>
> - ``int (*open)(struct uio_info *info, struct inode *inode)``:
> Optional. You might want to have your own :c:func:`open()`,
>
> base-commit: 1dc18801be29bc54709aa355b8acd80e183b03cd
> --
> 2.43.0
>

Cheers, Lorenzo