Re: [PATCH 4/4] rust: time: add `pr_warn_once!` for clamped delta in `fsleep`

[Greg KH <gregkh@linuxfoundation.org>]

On Thu, Feb 26, 2026 at 09:59:23PM +0900, FUJITA Tomonori wrote:
> On Thu, 26 Feb 2026 17:38:48 +0530
> Adarsh Das <adarshdas950@gmail.com> wrote:
> 
> > Add a warning when the delta is clamped to the maximum value and remove the TODO comment.
> > 
> > Signed-off-by: Adarsh Das <adarshdas950@gmail.com>
> > ---
> >  rust/kernel/time/delay.rs | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/rust/kernel/time/delay.rs b/rust/kernel/time/delay.rs
> > index b5b1b42797a0..0965fcb6eb80 100644
> > --- a/rust/kernel/time/delay.rs
> > +++ b/rust/kernel/time/delay.rs
> > @@ -35,7 +35,7 @@ pub fn fsleep(delta: Delta) {
> >      let delta = if (Delta::ZERO..=MAX_DELTA).contains(&delta) {
> >          delta
> >      } else {
> > -        // TODO: Add WARN_ONCE() when it's supported.
> > +        crate::pr_warn_once!("delta out of range, clamping to maximum\n");
> >          MAX_DELTA
> >      };
> 
> pr_warn_once() and WARN_ONCE() are different; WARN_ONCE() also dumps a
> stack trace, which is more appropriate here, I think.

WARN_ONCE() also will panic the machine if panic_on_warn is enabled.  As
it is done in a few billion Linux systems right now :(

So be very careful about that.

thanks,

greg k-h