Messages in this thread | | | Date | Wed, 22 Apr 2009 22:08:53 +0100 | From | Alan Cox <> | Subject | Re: Wait for console to become available, v3.2 |
| |
> Alright, I know you (Alan (Stern)) know about USB. I think someone else > mentioned Firewire. What other hotpluggable buses do we need to worry about > and how can we get them interested?
In theory any console can be hot pluggable - PCI-X hotplug video cards, hotplug serial ports. In fact right now bad things occur if you hot-unplug consoles.
> 2. All devices have been probed > If we exit for reason 2, it means that no such device is present, > and we go on to the do the appropriate thing for that device class.
USB has no notion of #2 really
> Yes, I think we absolutely exclude devices plugged in after boot. I think such > usage, if it needs to be supported, can be handled with hot plugging. I'm a > little squishy on whether we might to be able to hot plug USB consoles as I > have a request to support this, but I think it's a separate issue from > supporting hot pluggable boot devices and I'm not worrying about it now.
This still assumes you can tell the difference, but USB in particular is rather like undergraduate students - they turn up when they feel like it at some point after they get kicked into life.
I don't think that is a big problem because our bus model is basically that all devices are discovered asynchronously (increasingly so with Arjan's speed up patches). A console model therefore has to deal with console addition and removal being dynamic.
| |