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Full review at: https://netdev-ai.bots.linux.dev/sashiko/#/patchset/20261102122340.1160733-1-thnkslprpt@gmail.com?part=1 --- ptp: Report clock removal to poll waiters The patch adds a check of ptp->defunct to ptp_poll(), placed after poll_wait() has registered on tsev_wq. ptp_poll() now returns EPOLLERR when the clock is being removed, so a poll waiter that consumes the removal wakeup no longer stays blocked until timeout. > diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c > index f63b45f5ee6ae..01adc70ad97b4 100644 > --- a/drivers/ptp/ptp_chardev.c > +++ b/drivers/ptp/ptp_chardev.c > @@ -593,6 +593,9 @@ __poll_t ptp_poll(struct posix_clock_context *pccontext, struct file *fp, > > poll_wait(fp, &ptp->tsev_wq, wait); > > + if (READ_ONCE(ptp->defunct)) > + return EPOLLERR; > + [Severity: Low] This isn't a bug, but should the other accesses to ptp->defunct be annotated to match this new READ_ONCE()? The only writer still uses a plain store, so this load has no WRITE_ONCE() to pair with: drivers/ptp/ptp_clock.c:ptp_clock_unregister() { ... ptp->defunct = 1; wake_up_interruptible(&ptp->tsev_wq); ... } The other lockless reader in this file, ptp_read(), still uses plain loads: drivers/ptp/ptp_chardev.c:ptp_read() { ... if (wait_event_interruptible(ptp->tsev_wq, ptp->defunct || queue_cnt(queue))) return -ERESTARTSYS; if (ptp->defunct) return -ENODEV; ... } After this patch, ptp_poll() and ptp_read() read the same flag in two different ways. Other code in this subsystem pairs its annotations explicitly. For example, queue_cnt() in ptp_private.h notes that its READ_ONCE() is "Paired with WRITE_ONCE() in enqueue_external_timestamp(), ptp_read(), extts_fifo_show()". Would it be more consistent to use WRITE_ONCE(ptp->defunct, 1) in ptp_clock_unregister() and READ_ONCE() in ptp_read()? The other option is to leave the new check unannotated like the existing ones. > return queue_cnt(queue) ? EPOLLIN : 0; > } -- pw-bot: changes-requested