Re: Timed wait/sleep

[Haudy Kazemi]

On Jul 6 2007, Alex Roman wrote:

> Hello,
>
> Is there any mechanism to wait/sleep for a specified time in GRUB?
>
> The reason I need something like this is that, for the ATA driver I am
> working on, I need to be able to wait for a memory mapped register to
> change, but I don't want to wait indefinitely. I'd like to be able to
> have some sort of loop that will read the register, say, 10 times,
> with 10 ms pause in between the reads...
>
> I've searched for this and wasn't able to find anything in the source 
> code...
>
> If there isn't one, what would be the best way to implement something
> like this? Perhaps using the RTC, or straight loops? Would there be
> any use, besides my driver, in developing an RTC interface?

I'd avoid straight loops...with those you run into processor speed 
issues...runs too fast on new CPUs, runs too slow on old hardware. Of 
course I guess you could calibrate some straight loops to the RTC, and then 
use the loops rather than polling the RTC periodically, but I don't think 
the extra level of complication would provide any real benefit.

> Thanks!