Re: Strange atkbd messages with missing keyboard

From: Dmitry Torokhov
Date: Fri Feb 13 2004 - 17:49:49 EST


On Friday 13 February 2004 01:57 pm, Vojtech Pavlik wrote:
> On Fri, Feb 13, 2004 at 01:27:46PM -0500, Dmitry Torokhov wrote:

> > I see that we are not getting a NAK when querying ID but getting it while
> > setting LEDs (or even writing to the control register later). It seems
> > like controller's timeout is longer than our internal one so we getting
> > timeout signal from keyboard (which we convert to a NAK) too late.
>
> We don't convert it to a NAK, it comes as a NAK byte from the controller
> (generated by the controller), and with the timeout flag set.

Right, sorry I got confused with something else...

>
> > I wonder if changing timeout in atkbd_sendbyte to 400 or 500 ms will
> > cure the problem.
>
> It probably would, but it also would slow down the detection. I think we
> can simply ignore bytes with the timeout flag set in the atkbd_interrupt
> function when we're not expecting an ACK/NAK.
>

The problem with this approach is that if late NAK comes while we are
actually waiting for result of some other command it will interfere and
can cause misdetection.

--
Dmitry
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