Messages in this thread | | | Date | Fri, 12 May 2006 09:27:09 -0700 | From | Andrew Morton <> | Subject | Re: 3c59x vortex_timer rt hack (was: rt20 patch question) |
| |
Steven Rostedt <rostedt@goodmis.org> wrote: > > > > On Fri, 12 May 2006, Andrew Morton wrote: > > > > > > > The vortex_timer is a timeout, > > > > err, it's actually a function. > > OK, I meant vp->timer
That's a kernel timer.
> > > > > will it go off often? > > > > Every five seconds if the cable's unplugged. Every 60 seconds otherwise. > > > > OK, so the function is a service and not a fixup (or both). Hmm, so > latency is an issue.
yup. It's been five years, sorry - I'm struggling to remember why vortex_timer() needs to block the interrupt handler.
The chip is fairly stateful - that EL3WINDOW() thing selects a particular register bank and needs protection against other register readers. But we should avoid running EL3WINDOW() in the rx and tx interrupt handlers anyway - iirc the chip is designed to permit that.
Is tricky.
How come -rt cannot permit disable_irq() in there?
(I think the _reason_ it's disable_irq() is, yes, because it's infrequent and because it can hold off interrupts for a long time if we use spin_lock_irq()) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |