[parisc-linux] Re: MUX driver for multiple ports (lines)

[Ryan Bradetich]

Hello Christoph,

No, I still have not found any documentation on the
Serial Mux driver.  The work I did was referenced
off the HP-UX mux driver.

>From what I can see, the 0x80 (MUX_LINE_OFFSET)
is the offset between the mux registers for each
line.  I have not tried to hook up multiple lines
yet but I believe the skeleton is there.  Did the
box HPMC?  Can you get a TOC and read the IAOQ to
see what caused the crash?  Maybe we need to add
additional locking to the driver, etc.

The mux only operates in a polling mode.  The HP-UX
driver also polls (I don't see anywhere in the driver
where it could create/cause/catch an interrupt).

I will be out this weekend, but back early next week.
Let me know what you find, and I'll take a poke and
see if I can help!

Thanks,

- Ryan


On Fri, 2002-09-13 at 16:25, Christoph Plattner wrote:
> Hallo Ryan,
> 
> have you already got docu on the serial MUX board ?
> Or where do you have the information about `#define's
> from. Is the MUX_LINE_OFFSET (= 0x80) the key point.
> 
> I have tried to access the board at
> 	membase + MUX_OFFSET + line * MUX_LINE_OFFSET,
> but the first write access to /dev/ttyB1 results in
> a hang up (completely, even no network interrupts
> were processed !).
> 
> Operates the MUX driver in polling mode ? Not in IRQ mode ?
> 
> Christoph
> 
> -- 
> -------------------------------------------------------
> private:	christoph.plattner@gmx.at
> company:	christoph.plattner@alcatel.at
>