[PATCH] arm/imx: use Kconfig choice for low-level debug UART selection

Russell King - ARM Linux linux at arm.linux.org.uk
Sun Aug 21 14:17:28 EDT 2011


On Sun, Aug 21, 2011 at 01:59:44PM -0400, Nicolas Pitre wrote:
> On Sun, 21 Aug 2011, Russell King - ARM Linux wrote:
> > I never liked the idea of coupling this into earlyprintk - and I think
> > I said so at the time.  I'll say it again:
> > 
> > The LL DEBUG stuff is there to be able to do low level "it won't boot"
> > debugging.  It's not there as a user option.  You are supposed to know
> > exactly what you are doing when using the option.
> > 
> > If we're going to start having earlyprintk be an argument against this,
> > I'll simply rip out the earlyprintk coupling to LL debug, and people
> > can go back to patching printk.c to make this work.
> 
> But we need a functional earlyprintk.  It has to be usable by simple 
> _users_ who are not developers.  ARM is not going to remain this obscur 
> embedded architecture forever.

I repeat: that is not the point of DEBUG_LL.  DEBUG_LL is there for
*developers* to debug their initial board bringup.  Nothing else.

I repeat: I'm not going to have DEBUG_LL buggered up by do-gooders
and people wanting BIOS shite and then have to re-invent it so that
we can have decent debugging again.  That's NOT going to happen.  No
way at all.

> > > One could argue
> > > that this option is for people who exactly know what they do only.
> > 
> > It _IS_ there for people who know what they're doing.  That's something
> > I keep on saying about the LL debug stuff.  It's there to allow people
> > to debug the early startup of the kernel.  It's not there for users.
> 
> That is not sufficient.

Tough.  That's the way it is and it has to be lived with.  Early board
bring up has absolutely nothing to do with users.  If users are doing
early board bringup, they are kernel developers by definition.



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