Re: lspci/oldproc new card

Florian Lohoff (flo@rfc822.org)
Mon, 31 May 1999 16:14:23 +0200

On Mon, May 31, 1999 at 11:53:02AM +0200, Martin Mares wrote:
>
> PLX9060SD is a generic PCI controller chip, so it won't reveal anything
> about how does the card really work. I suspect there exists no Linux driver.
> Can you look at the other chips on the card?

Have already begun writing a driver

PLX9060SD is from the pdf from plxtech a generic PCI2Local chip.
Also on the card are (2x) CD1865 (Cirrus Logic 8 Port Serial Chips
already supported in specialix.c)

This works already :

- Transmitting
- Hardware Handshake
- Interrupt Bottom Half
- tty_driver

Now i am working on Receiving, Software Handshaking and
the complete termios, ioctl support, things i havnt understood a bit.

But i am optimistic that i have a full working driver within a week
or something - Ill send a version as soon as i am able to
start minicom, type bullshit without swallowed characters, Oppses
etc ...

I am currently a bit confused in Locking issues (SMP/Interrupt etc)

Because the CD1865 contains 8 Serial Ports and their registers are
multiplexed (read: you can only read one ports registers at a time)
so you have to lock the chip for concurrent access. Also
you need locking for transmit buffer changes (char count, head, tail etc)
and i am currently unaware how to do this

spin_lock_irqsave() and friends ...

But from reading in the serial.c/specialix.c i cant see them
using those and so beeing not SMP safe (in my view) and
getting more confused ...

Flo

-- 
Florian Lohoff		flo@rfc822.org		      	+49-5241-470566
Good, Fast, Cheap: Pick any two (you can't have all three).  (RFC 1925)


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