On Sat, 1 Dec 2007, Benjamin Herrenschmidt wrote:

On Fri, 2007-11-30 at 13:10 -0600, T Ziomek wrote:

quoted

quoted

This patch makes the early debug option force the console loglevel
to the max. The early debug option is meant to catch messages very
early in the kernel boot process, in many cases, before the kernel
has a chance to parse the "debug" command line argument. Thus it
makes sense when CONFIG_PPC_EARLY_DEBUG is set, to force the console
log level to the max at boot time.

  . . .

quoted

+#ifdef CONFIG_PPC_EARLY_DEBUG
+     console_loglevel = 10;
+#endif
}

The change makes sense, but wouldn't it also make sense to note it in
arch/powerpc/Kconfig.debug?  Otherwise it's really hard to figure out
why,
after bringing up a new board, removing "debug" from the kernel cmd
line
does, well, nothing.

Possibly, though you aren't supposed to leave EARLY_DEBUG enabled
once you are done debugging :-)

I'm probably not the only person that would turn it on when needed, think
"well, no harm in leaving it on for the rest of my development, and it
might be handy; just turn it off when we're done".

It's these kind of non-obvious but undocumented things that make a lot of
OSS code a pain to work with for non-experts [1].  What's the harm in
giving folks a heads-up?

[1] : And I don't just mean newbies...I mean anybody who doesn't live in
        the code on a daily basis year-round.

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