On Tue, 2007-02-20 at 08:46 -0600, Josh Boyer wrote:

On Tue, 2007-02-20 at 15:16 +0100, Arnd Bergmann wrote:

quoted

On Tuesday 20 February 2007 15:05, Josh Boyer wrote:

quoted

Which probably has something to do with the of_serial driver being used
now.  Just an FYI.

If you want to use of_serial together with serial console, you need
to make sure that the detection logic in arch/powerpc/kernel/legacy_serial.c
finds the port. It currently finds the serial port on axon, but that
requires that the bus it's on is of type "opb" and the device itself
is listed as "stdout" and has type "serial" and is compatible with
"ns16750" (note: the others look for "ns16550" here).

The ebony dts has the ports as ns16550.  That is required for the
bootwrapper to find the port to use for it's output at the moment.

And the ebony dts also has the a bus type of "ibm,opb" as well.

I hacked legacy_serial.c to look for ns16550 compatible devices with a
parent OPB node of type "ibm,opb" and I got serial output on the Ebony
board even with of_serial turned off.

We should look for both "ns16550" and "ns16750" compatible devices in
legacy_serial.c.  As for the bus type, we could look for both types or
the ebony.dts could change to use "opb" instead of "ibm,opb".

josh