Qian Cai [off-list ref] writes:
At the beginning of setup_64.c, it has,
#ifdef DEBUG
#define DBG(fmt...) udbg_printf(fmt)
#else
#define DBG(fmt...)
#endif
where DBG() could be compiled away, and generate warnings,
arch/powerpc/kernel/setup_64.c: In function 'initialize_cache_info':
arch/powerpc/kernel/setup_64.c:579:49: warning: suggest braces around
empty body in an 'if' statement [-Wempty-body]
DBG("Argh, can't find dcache properties !\n");
^
arch/powerpc/kernel/setup_64.c:582:49: warning: suggest braces around
empty body in an 'if' statement [-Wempty-body]
DBG("Argh, can't find icache properties !\n");
Neither of those sites should use DBG(), that's not really early boot
code, they should just use pr_warn().
And the other uses of DBG() in initialize_cache_info() should just be
removed.
In smp_release_cpus() the entry/exit DBG's should just be removed, and
the spinning_secondaries line should just be pr_debug().
That would just leave the two calls in early_setup(). If we taught
udbg_printf() to return early when udbg_putc is NULL, then we could just
call udbg_printf() unconditionally and get rid of the DBG macro entirely.
cheers