Re: Adding PCMCIA support to the kernel tree -- developers needed.

[Oliver Neukum <Oliver.Neukum@lrz.uni-muenchen.de>]

> > That is, sysctl to set the kernel "hotplug" string?  Would that
> > then invoke "/sbin/hotplug start", or would something else
> > need to make sure all the relevant subsystems are well enough
> > initialized?
>
> I assumed this meant the threads would be spawned and wait, as I
> suggested, but instead of waiting till the rootfs is mounted, they'd wait
> for an explicit trigger from userspace, whether that's setting the
> 'hotplug' string or a new 'hotplug_trigger' sysctl. But that means we have
> kernel threads collecting waiting for userspace to trigger them, and I'm
> not sure that's a good idea.

I have thought more about it.
You cannot simply wait. In fact you need to cancel those requests to user 
space. If you simply replay the sequence of events you have scripts acting on
device nodes that have already been reused. Simple waiting is even worse. 
You'd loose the defined order of events. The result wouldn't even be 
deterministic.

On the activation of user space hotplugging support plugging events must be 
faked and must reflect current hardware. Probably user space should be 
notified of the fact that these devices may already be in use.

	Regards
		Oliver


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