Re: [PATCH v7 1/1] pps: pps-gpio: split IRQ handler into hardirq timestamper + threaded handler

[Andrew Morton <akpm@linux-foundation.org>]

On Mon,  1 Jun 2026 17:44:09 -0700 Calvin Owens <calvin@wbinvd.org> wrote:

> Split the pps-gpio interrupt handler into a primary (hardirq) handler
> that captures the PPS timestamp at interrupt entry, and a threaded
> handler that processes the event. This produces the same two-part
> handler structure on both PREEMPT_RT and non-RT kernels.
> 
> On non-RT kernels the threaded portion runs immediately after the
> primary, with no behavioral change compared to the previous
> single-handler implementation.
> 
> On PREEMPT_RT, where interrupt handlers are force-threaded by default,
> the previous single-handler implementation captured the timestamp
> inside the threaded portion, after IRQ-thread scheduling delay. With
> the split, the timestamp is captured in true hardirq context as it is
> on non-RT kernels, eliminating a significant source of PPS jitter on
> RT systems.

Thanks, I'll add this to mm.git's mm-nonmm-unstable branch.  This means
it will get linux-next exposure immediately.

All being well, I'll later move this into the non-rebasing
mm-nonmm-stable branch with the intent to upstream it in the next merge
window.

Sashiko AI review might have found some issues, one of them
pre-existing.  Please check it out:

	https://sashiko.dev/#/patchset/2e32729029fbf6977ecf04665eb00f2efd3e2c17.1780359378.git.calvin@wbinvd.org