Re: lanana: Add major/minor entries for PPC QE UART devices

Timur Tabi
2007-02-28T17:04:13Z

Dan Malek wrote:

> I don't know the origin of this thread, but none of
> that looks correct. Today, there can be up to 8
> CPM UART devices, 6 on CPM/CPM2 and 8
> on the QE. If ttyCPM0 starts at minor 46, they
> should be at least monotonically incrementing
> up to ttyCPM7 with minor 53.

Minor nit: On the QE, they'll be called ttyQE0 through ttyQE7.

I agree that the CPM and the QE should share the same starting minor number, so that
ttyCPM0 has the same major/minor number as ttyQE0, since it's not possible to have a CPM
and a QE on the same device. However, ttyCPM0 is currently assigned to 46, and device 50
is an Altix serial card. The only way to give the CPM 6 or 8 slots without moving it is
to overlap the Altix card.

Now I don't know anything about the Altix card, so I don't know if it's possible to use
that card on a system with a CPM or a QE. If it isn't, then I don't know if overlapping
minor numbers is still a problem.

(Note that the Altix card has a range of 50-81, which is pretty big.)

If we move CPM/QE to 192, then I can change the CPM device driver to reflect that, but I
don't know what that means for older kernels.

--
Timur Tabi
Linux Kernel Developer @ Freescale