Early boot problem with MPC8247 and Linux 2.6.26

[Chris Skepper]

On Wed, 27 Aug 2008, Scott Wood wrote:

> On Wed, Aug 27, 2008 at 02:30:47PM +0100, Chris Skepper wrote:
>> I just left CONFIG_PPC_EARLY_DEBUG_CPM_ADDR at the default value for CPM2?
>> Is that likely to be correct for SMC1?  (I tried looking in the MPC8272
>> reference manual, but couldn't find it.)
>
> The value depends on how the port was set up by firmware (or by the
> bootwrapper).  It should be set to wherever the descriptor is, and there
> should only be one descriptor that loops back on itself.

Hi Scott,

Thanks so much for your help so far.  I was able to find out this address 
from the bootloader and get some output on the early debug console which 
was very pleasing.  It now gets as far as console_init() called from 
init/main.c, which completes but then any printk seems to stall it and 
you get no more output.

I am using SMC1 and have this in the DTS file for the linux,stdout-path:

serial at 11a80 {
 	device_type = "serial";
 	compatible = "fsl,mpc8247-smc-uart",
 	            "fsl,cpm2-smc-uart";
 	reg = <0x11a80 0x20 0x87fc 2>;
 	interrupts = <4 8>;
 	interrupt-parent = <&PIC>;
 	fsl,cpm-brg = <7>;
 	fsl,cpm-command = <0x1d000000>;
};

Any ideas what sorts of things I should check next?

Cheers,

Chris.