Subject: Re: [PATCH] of_serial: ignore unknown serial port

From: Arnd Bergmann <[email-masked]>
Date: Wed, 6 Jun 2007 15:01:15 +0200

On Wednesday 06 June 2007, Segher Boessenkool wrote:
> >
> > Is this a bugfix that needs to go in 2.6.22?
> 
> This potentially breaks lots of other platforms, so no
> please, put it in early in the next cycle and give those
> others time to recover from this change.

I would expect that the bugfix is relatively harmless, as the
driver is rather new and there can only be a very small set
of users. All the OF based systems should be working fine
either way, because they already have legacy_serial, and
the dtc sources that come with the kernel all list the 
serial ports as compatible to either "ns16550", "cpm_uart",
"marvell,mpsc", or "mpc5200-psc-uart". In the first case
of those four, the change is harmless, for the other three
it is a valid bug fix.

It probably only makes a difference for 52xx in the case that
you have CONFIG_SERIAL_OF_PLATFORM=y and CONFIG_SERIAL_MPC52xx=m.
In that configuration, you get the same bug that Kou Ishizaki
observed on celleb without this fix.

	Arnd <><