Subject: Re: cardbus code without busy wait
To: Lennart Augustsson <lennart@augustsson.net>
From: Jason Thorpe <thorpej@nas.nasa.gov>
List: tech-kern
Date: 01/19/2000 10:08:38
On Wed, 19 Jan 2000 10:45:33 +0100
Lennart Augustsson <lennart@augustsson.net> wrote:
> > Oh, I made a mistake... I worry about card attaching
> > sequence at boot time. At boot time, kernel thread cannot
> > be used when inserted device is used to boot kernel up.
> > Which context is used during the boot sequence?
>
> Oh, OK. Yes, if you want to be able to attach at boot time you need
> to busy wait. But that can be hidden away in some wait routine that
> checks for the `cold' variable.
> You can also delay attaching until the attach thread is running. I thought
> that was what the cardbus code did already? Unless you give `flag 1' on
> in the config file. I stole this idea for the USB code. :)
that presents another problem ... you can't use PCMCIA/CardBus cards for
the root device in that case.
Probably what you could do is use config_interrupts(), at which point tsleep()
can work since the clock is running (you're on proc0's thread context).
-- Jason R. Thorpe <thorpej@nas.nasa.gov>