Re: getting timestamp of last interrupt?

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Date:	Mon, 06 Oct 2003 21:05:13 +0200
To: root@chaos.analogic.com

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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• Previous message: Krzysztof Benedyczak: "Re: POSIX message queues"
• In reply to: Richard B. Johnson: "Re: getting timestamp of last interrupt?"
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