Trouble with SCC UART ports when moving from ppc to powerpc

[Laurent Pinchart]

On Thursday 20 March 2008 16:08, Scott Wood wrote:
> On Thu, Mar 20, 2008 at 02:39:56PM +0100, Laurent Pinchart wrote:
> > I'm working on a patch. I'm not sure how to handle the early udbg printk
> > problem, so the first version will just ignore it.
>
> udbg printk is extremely useful... I'd not be fond of it breaking.

I don't want to kill it either. What I meant is that my first patch will not 
care about udbg so that I can get feedback about the CPM serial driver part. 
I'll then see how to make udbg fit into that.

> Perhaps we should stick more initialization into the cpm udbg code, so it
> isn't so dependent on the bootloader setup... though we'd have push the
> CPM reset and SMC allocation earlier in such a case.

When SMC1 is used as a serial console, SMC1 is the first CPM dpram allocation 
user. This means the CPM dpram allocator will allocate a buffer at the 
beginning of the dpram. As he SMC controller will already be using the 64 
first bytes of the dpram, it will not see any difference when being 
reinitialized.

This of course depends on the boot loader allocating parameter ram at the 
beginning of the dpram for SMC1, but we already depend on that if I'm not 
mistaken.

-- 
Laurent Pinchart
CSE Semaphore Belgium

Chaussée de Bruxelles, 732A
B-1410 Waterloo
Belgium

T +32 (2) 387 42 59
F +32 (2) 387 42 75
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: not available
URL: <http://lists.ozlabs.org/pipermail/linuxppc-dev/attachments/20080320/0ef53392/attachment.pgp>