[PATCH 2/6] arm/imx6q: add core definitions and low-level debug uart

[Nicolas Pitre]

On Wed, 7 Sep 2011, Russell King - ARM Linux wrote:

> On Wed, Sep 07, 2011 at 02:36:35PM +0200, Uwe Kleine-König wrote:
> > But only if the image doesn't support imx6q, right? Anyhow, I hope
> > imx6q_map_io isn't called for pre-imx6q SoCs. Ah, and I hope we don't
> > need to argue here as Russell doesn't like the new DEBUG_LL changes :-)
> 
> I have no problem with the Kconfig menu approach or existing approaches
> to DEBUG_LL.  What I have an objection to is trying to stuff the
> information for it into places which ultimately render the facility
> useless for its intended purpose - to permit debugging the _really_
> _early_ assembly code.
> 
> That is what it was written for: if we introduce complicated ways to
> put behind it, we'll need to come up with a completely new debugging
> infrastructure to debug the now buggered debugging infrastructure.

For the record I now agree with Russell.

In order to have early serial output that works across multiple SOCs in 
the same kernel image intended to non developers we'll have to add a 
parallel infrastructure.  Keeping the DEBUG_LL code as simple as 
possible for developers is the way to go (and that might be needed to 
debug that parallel infrastructure).


Nicolas