Hi, Jiri,

Thanks for your feedback.

On Thu, Jan 29, 2026 at 3:41 AM Jiri Slaby [off-list ref] wrote:

Have you checked this is not included in any relevant userspace? How?
Hints: debian code search, github...

The only references in Debian Code Search outside the kernel are in
libexplain (which has a configure test for the presence of this header
and should be fine), lists of files, and lists of ioctls, e.g. in
strace, which do not include the header itself.
The only reference of note on GitHub (although I can't look past the
5th page of results) is in
https://github.com/sunfishcode/linux-raw-sys, which includes every
Linux header as part of its binding generation process, and has
already had to drop other headers as they were removed:
https://github.com/sunfishcode/linux-raw-sys/commit/a804ac01491f63c8ce879ef27254d27dfcf89ff2
The package ships a generated version of the bindings, so the header
is not needed by normal users.
If this commit is merged, I will send a pull request to remove
<linux/synclink.h> from the code.
It was also used in old versions of
https://github.com/jerome-pouiller/ioctl but recent versions
automatically generate the list of ioctls on every build.
Is this okay with you, or should I send a new version of the patch
with <linux/synclink.h> retained?

I would just drop the line, removing one conflicting entry. The letter
is not going to be dead.

Or is this Dead note some ioctl-number's policy?

It was used in quite a few other entries, so I just followed their example.

This paragraph actually talks about long removed synclink.c, removed in:
   a1f714b44e34 tty: Remove redundant synclink driver

Good to know.

Ethan