Re: [PARPORT] Multiple ppuser drivers

Andrea Arcangeli (
Fri, 17 Jul 1998 17:00:23 +0200 (CEST)

On Thu, 16 Jul 1998, Tim Waugh wrote:

>I can't think of a way of knowing which handle to use if more than one
>person is allowed to have /dev/parport0 open at once -- I can't even use

We could allow only one process to open /dev/parportx at a time.

If you like to have more than one ppuser process that schedule the same
parport I think it' s better define something like:

dev name minor
parport0a 0
parport0b 1
parport0c 2
parport0d 3
parport1a 4

This isn' t malleable but it' s a rock solid (maybe a bit too much ;-)

I have not thought about this a lot (nor I have read the code), it' s only
an idea and I could be wrong.

BTW, we just know that minor numbers are only 256, but with 2.3 I hope
somebody will change the ext2 inode to handle 64bit of minor and major
numbers (to get rid of other problems too). There is also devfs that would
_workaround_ the problem.

>the inode number in case some bozo created a parport0 device node on
>another filesystem!

Are the dentries unique?

Andrea[s] Arcangeli

-- To unsubscribe, send mail to: --
-- with the single word "unsubscribe" in the body of the message. --

This archive was generated by hypermail 2.0b3 on Wed 30 Dec 1998 - 10:18:00 EST