Re: getting timestamp of last interrupt?

[Hans-Georg Thien]

Richard B. Johnson wrote:

> On Mon, 6 Oct 2003, Hans-Georg Thien wrote:
>
> > [...]
> > I'm writing a kernel mode device driver (mouse).
> >
> > In that device driver I need the timestamp of the last event for another
> > kernel mode device (keyboard).
> >
> > I do not care if that timestamp is in jiffies or in gettimeofday()
> > format or whatever format does exist in the world. I am absolutely sure
> > I can convert it somehow to fit my needs.
> >
> > But since it is a kernel mode driver it can not -AFAIK- use the signal()
> > syscall.
> >
> > -Hans
>
>
> Then it gets real simple. Just use jiffies, if you can stand the [...]
I fear that there is still some miss-understanding. Jiffies are totally 
OK for me. I can use them without any conversion.

I'll try to formulate the problem with some other words:

I hope that there is is something like a "jiffie-counter" for the 
keyboard driver, that stores the actual jiffies value whenever a 
keyboard interrupt occurs.

I hope too, that there is a way to query that "jiffie-counter" from 
another kernel driver, so that I can write something like


mymouse_module.c

...
void mouse_event(){

   // get the current time in jiffies
   int now=jiffies;

   // get the jiffie value of the last kbd event
   int last_kbd_event= ????;  // ... but how to do that ...

   if ((now - last_kbd_event) > delay) {
	do_some_very_smart_things();
   }
  }
...

-Hans


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