Re: Problems writting a CHAR Driver with interruptible_sleep (wait_

Raul Dias (raul@dias.com.br)
Mon, 16 Aug 1999 16:38:58 -0300 (EST)


On 16 Aug, Matthew Kirkwood wrote:
> On Mon, 16 Aug 1999, Raul Dias wrote:

>> It will be thousands of readings in a second, so I can't "hang" the
>> machine.
>
> Oh. Out of curiosity, how do you expect to do thousands of reads per
> second when you have a thousandth of a second between them? :)

Well, I changed it to udelay(80) the time the Board need to read data.
It gave me 103 reads in one jiffy.
103*100 = 10300 reads/sec.

So, that's the problem I *need* to differenciate time here - 103
readings with the same time doesn't help :-).

> Seriously, you probably want to look at the PC speaker driver patch -
> this did some pretty hairy modifications to the timer interrupt stuff
> to have it use the RTC instead of the usual PC timer chip, I think.

Ok. Now a stupid question :-)
How do I use RTC? Where can I find any documentation? Example (besides
the PC Speaker one.

>
> Platforms. The TSC is an i386 thing, though other architectures often
> have similar features. Either way, it's only really useful for
> busy-waiting and accurate timing measurements anyway.
>
>> Where can I find more info about it?
>
> grep the source for CONFIG_M586TSC, or visit www.intel.com.

I will :-)
Is there any function I can use?

Raul Dias

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