Re: [PATCH] USB: cdc-acm: fix racy TIOCMIWAIT implementation

[Oliver Neukum]

On 07.09.26 15:03, Johan Hovold wrote:
> On Mon, Sep 07, 2026 at 02:46:16PM +0200, Oliver Neukum wrote:
> >

> > We could do that and it would indeed be simpler.
> >
> > But it would change the semantics so that past status changes
> > no longer show up in TIOCMIWAIT. Is that really a good idea?
>
> Yes, as the current behaviour is both non-standard and inconsistent.
>
> If you have multiple tasks waiting waiting on status change, then only
> one of them will detect it, for example.
>
> And if there are multiple changes (before or during TIOCMIWAIT) events
> may be lost too.

Very well. Ample reasons. Do you have a patch or do you want me to fix it?

	Regards
		Oliver