On Wed, Aug 24, 2011 at 08:09:34AM -0700, Greg KH wrote:

On Wed, Aug 24, 2011 at 03:54:00PM +0100, Jamie Iles wrote:

quoted

On Wed, Aug 24, 2011 at 04:45:16PM +0200, Arnd Bergmann wrote:

quoted

On Wednesday 24 August 2011, Jamie Iles wrote:

quoted

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.

quoted

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, that would be great (and sorry for the breakage!).

Jamie