Re: [PATCH] serial driver PMC MSP71xx, kernel linux-mips.git mast er

From: Marc St-Jean
Date: Wed Jan 24 2007 - 16:11:12 EST


Sergei Shtylyov wrote:
> Hello.
>
> Marc St-Jean wrote:
>
> >> >>This I would hope you can hide in the platform specific
> >> >>serial_in/serial_out functions. If you write the UART_LCR save it in
> >> >>serial_out(), if you read IER etc.
>
> >> > I couldn't find hooks for platform specific serial_in/out functions.
>
> >> It's because there are none. :-)
>
> >> > Do you mean using the up->port.iotype's in serial_in/out from 8250.c?
>
> >> Not sure what Alan meant, but this seems the only option for now.
>
> > That's the conclusion I came to. I've rewritten the patch to use
> port.type
> > instead of iotype since one of the fix is SoC and not UART specific.
> I guess
>
> I failed to folkow your logic. :-)

No longer matters as I can't use port.type. See next comment.

> > I could use both iotype and type with a test on each for the appropriate
> > bug, what do you recommend?
>
> I think iotype would be enough. You can't pass type for platform
> devices
> anyway, IIRC (the thing I don't quite like).

I just found that out the hard way, it get's overwritten during autoconfig* and
ends up back at PORT_16550A.

I'm now trying to use my own iotype = UPIO_DWAPB and I've added it to all cases
that check for UPIO_MEM. However at boot time I'm getting:
"serial8250: ttyS0 at *unknown* (irq = 27) is a 16550A".
It looks like something outside of 8250.c must be checking for UPIO_MEM, I'm
looking into it.

>
> >> >>And we might want to add a void * for board specific insanity to
> the 8250
> >> >>structures if we really have to so you can hang your brain damage
> >> >>privately off that ?
>
> >> > Sounds good to me, it would give us a location to store the
> address of the
> >> > UART_STATUS_REG required by this UART variant.
>
> >> I doubt we really need to *store* it somewhere. Isn't it an fixed
> offset
> >>from UART's base (I haven't seen the header)?
>
> > Unfortunately it's not a constant offset from the UART in the SoC
> register
>
> Hm...
>
> > space. I've used Alan suggestion and added a classic, on some other
> OSes %-|,
> > void "user" pointer.
>
> Only do not do it under #ifdef.

Understood, getting rid of them is why I started this thread.

Marc
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