Messages in this thread | | | Date | Fri, 20 Jun 2008 18:37:56 +0200 | From | Stefan Richter <> | Subject | Re: [RFC/PATCH] usb-storage: wait for device scanning before mounting root |
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Alan Stern wrote: > New USB devices can appear at any time. None are present when the > system is started; they are all detected dynamically by the khubd > thread. > > While I'm not familiar with the details of any other hotpluggable > buses (like Firewire), I imagine much the same is true for them.
It's very similar with FireWire. FireWire devices announce SBP-2 target capability (if they have it) after they became ready. The ieee1394 or firewire core then scans or re-scans them in a process context. Then upper layer drivers like the SBP-2 driver are matched, bound, probed.
If SBP-2 targets went through a power state change, they typically first power everything up (spin up media etc.) before they announce their protocol capabilities, and this may of course take a while. Before that they just are inaccessible, and it is unknown whether they could become candidates for access by upper layer drivers. -- Stefan Richter -=====-==--- -==- =-=-- http://arcgraph.de/sr/
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