Re: [PATCH v8 05/14] rust: hrtimer: allow timer restart from timer handler

From: Benno Lossin
Date: Fri Feb 21 2025 - 05:16:53 EST


On 21.02.25 10:09, Andreas Hindborg wrote:
> "Benno Lossin" <benno.lossin@xxxxxxxxx> writes:
>
>> On 18.02.25 14:27, Andreas Hindborg wrote:
>>> This patch allows timer handlers to report that they want a timer to be
>>> restarted after the timer handler has finished executing.
>>>
>>> Also update the `hrtimer` documentation to showcase the new feature.
>>>
>>> Signed-off-by: Andreas Hindborg <a.hindborg@xxxxxxxxxx>
>>> ---
>>> rust/kernel/time/hrtimer.rs | 28 +++++++++++++++++++++++++++-
>>> rust/kernel/time/hrtimer/arc.rs | 4 +---
>>> 2 files changed, 28 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/rust/kernel/time/hrtimer.rs b/rust/kernel/time/hrtimer.rs
>>> index b2a3130bc21d7..e342193f985eb 100644
>>> --- a/rust/kernel/time/hrtimer.rs
>>> +++ b/rust/kernel/time/hrtimer.rs
>>> @@ -183,7 +183,7 @@ pub trait HrTimerCallback {
>>> type CallbackTargetParameter<'a>;
>>>
>>> /// Called by the timer logic when the timer fires.
>>> - fn run(this: Self::CallbackTargetParameter<'_>)
>>> + fn run(this: Self::CallbackTargetParameter<'_>) -> HrTimerRestart
>>> where
>>> Self: Sized;
>>> }
>>> @@ -278,6 +278,32 @@ unsafe fn start(self_ptr: *const Self, expires: Ktime) {
>>> }
>>> }
>>>
>>> +/// Restart policy for timers.
>>> +pub enum HrTimerRestart {
>>> + /// Timer should not be restarted.
>>> + NoRestart,
>>> + /// Timer should be restarted.
>>> + Restart,
>>> +}
>>> +
>>> +impl From<bindings::hrtimer_restart> for HrTimerRestart {
>>> + fn from(value: u32) -> Self {
>>> + match value {
>>> + bindings::hrtimer_restart_HRTIMER_NORESTART => Self::NoRestart,
>>> + _ => Self::Restart,
>>> + }
>>> + }
>>> +}
>>> +
>>> +impl From<HrTimerRestart> for bindings::hrtimer_restart {
>>> + fn from(value: HrTimerRestart) -> Self {
>>> + match value {
>>> + HrTimerRestart::NoRestart => bindings::hrtimer_restart_HRTIMER_NORESTART,
>>> + HrTimerRestart::Restart => bindings::hrtimer_restart_HRTIMER_RESTART,
>>> + }
>>> + }
>>> +}
>>
>> Do drivers need these impls? If no, I would prefer a private conversion
>> function just for the abstraction.
>
> No, drivers would not need these. I can hide them.

Sounds good, you can add:

Reviewed-by: Benno Lossin <benno.lossin@xxxxxxxxx>

---
Cheers,
Benno