Re: [PATCH] tty: 8250_dw: fix build error for CONFIG_SERIAL_8250=m

[Greg KH <greg@kroah.com>]

On Wed, Aug 24, 2011 at 03:54:00PM +0100, Jamie Iles wrote:
> On Wed, Aug 24, 2011 at 04:45:16PM +0200, Arnd Bergmann wrote:
> > On Wednesday 24 August 2011, Jamie Iles wrote:
> > > Allow 8250_dw to be built as a module and export serial8250_handle_irq
> > > so that 8250 can still be built as a module.  This prevents the
> > > following build failure:
> > > 
> > > drivers/built-in.o: In function `dw8250_handle_irq':
> > > 8250_dw.c:(.text+0xcad9c): undefined reference to `serial8250_handle_irq'
> > 
> > I think this won't fix the bug that Stephen was reporting, it will only
> > make the error message go away but it won't work in the end: When
> > CONFIG_SERIAL_8250_DW is set to 'm', the declaration of
> > serial8250_use_designware_io now gets stubbed out from of_serial.ko,
> > meaning that the 8250_dw module becomes useless.
> > 
> > At the very least you also need to export the serial8250_use_designware_io
> > symbol and check for CONFIG_SERIAL_8250_DW_MODULE in the header.
> 
> Ahh, I didn't realise that this would define 
> CONFIG_SERIAL_8250_DW_MODULE rather than CONFIG_SERIAL_8250_DW.
> 
> > When go go to such length, I think the approach I initially advocated
> > (making 8250_dw a standalone platform_driver like of_serial) will be
> > nicer.
> 
> OK, in hindsight that does seem like a much better option.  I'll spin a 
> separate platform_driver instead.
> 
> Greg, I'm not sure how to best handle this, do you want patches to 
> revert:
> 
> 	tty: serial8250: add helpers for the DesignWare 8250
> 	tty: of_serial: add support for the DesignWare 8250
> 
> or can these be dropped?

I'll go revert them myself, as that's easiest, right?

thanks,

greg k-h