Re: [RFC/RFT] Remove polling timer from i8042

[Vojtech Pavlik <vojtech@suse.cz>]

On Fri, Jul 28, 2006 at 08:57:31AM -0400, Dmitry Torokhov wrote:

> On 7/27/06, Vojtech Pavlik <vojtech@suse.cz> wrote:
> >On Thu, Jul 27, 2006 at 12:29:04AM -0400, Dmitry Torokhov wrote:
> >> Hi,
> >>
> >> OK, I had it in works for quite some time and Dave's talk in Ottawa
> >> made me finish it ;)
> >
> >Good work.
> >
> >However I believe you need to test the AUX IRQ in this case before you
> >use it, otherwise you'll have a lot of people with non-working keyboards
> >(the input queue is shared), and probably also non-working PCI cards
> >(BIOSes like to assign IRQ12 to PCI if no mouse is detected by the
> >BIOS).
> >
> 
> What do you mean by testing AUX IRQ? Use I8042_CMD_AUX_LOOP to see if
> interrupt fires off? The new code releases IRQ if it can't find a
> working AUX port...

Exactly. Not that a character arrives and can be polled for, but that
the interrupt actually gets raised. It can be routed to nowhere and
we'll never know, our buffers will be full and keyboard will be stuck.

> >You'll see whether this test is necessary if a lot of people report
> >problems without i8042.noaux.
> >
> >That can only be seen after extensive testing on a lot of machines,
> >though. Fortunately 386's and 486's are more or less extinct now, and
> >with them a lot of the weirder keyboard controllers.
> 
> I think I will forward the patch to Andrew and we will see how bad it
> is. It works on couple of boxes here but I don't have a lot of
> hardware to test on...

Yup.

-- 
Vojtech Pavlik
Director SuSE Labs