On Mon, 15 Jun 2015, Mason wrote:
> A) process-context kernel thread fills a FIFO and calls down(&fifo_empty);
> B) ISR handles the FIFO-empty interrupt with up(&fifo_empty);
>
> However, in case something goes wrong and the interrupt never fires,
> I don't want the process to be stuck in an uninterruptible sleep.
>
> Perhaps I can set a tiny timeout (e.g. 10 µs) and not worry about
> the interruptible part for such a small duration? (Hmm, __down_common
> calls schedule_timeout, which is jiffies-based. I don't think there
> is a hrtimers flavor. So µs timeouts would be off the table?)
>
> Or I could use the interruptible version, and let the user kill the
> operation if necessary.
Use a completion.
Thanks,
tglx
