Messages in this thread |  | | Date | Wed, 16 May 2001 16:55:38 -0700 | From | "H. Peter Anvin" <> | Subject | Re: LANANA: To Pending Device Number Registrants |
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Richard Gooch wrote: > > OK. How do you figure on dealing with the problem of multiple > high-level drivers talking to the same device? How does sr.o "know" > that this is also a CD-RW? How does sg.o "know" that this is also a > tape? >
At some point something talks to the device -- in this case, it's the SCSI layer. Follow the interfaces in the kernel and it becomes obvious.
> Where does the responsibility lie for figuring out the capabilities? > > Further, which device node/fs/driver exports the capability list? > > And what about locking between drivers?
Orthogonal issue. You may want a locking mechanism, but it almost certainly should not be automatic.
Note that especially ide-scsi is a good example on how *not* to do things. The fact that you have to choose one of two interfaces for different operations (I can't use a CD-writer in the default configuration!) is insane.
-hpa
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