[POWERPC] Document when printk is useable
authorBenjamin Herrenschmidt <benh@kernel.crashing.org>
Wed, 7 May 2008 00:00:56 +0000 (10:00 +1000)
committerPaul Mackerras <paulus@samba.org>
Fri, 9 May 2008 10:22:58 +0000 (20:22 +1000)
commit24d9649574fbe591fdfa6b00893d4096f513e539
treede6b2a4b4e1d7754d4100404b4d74574be0a608e
parent1b70c5a6491dd02263e6d104b72d9b536f987021
[POWERPC] Document when printk is useable

When debugging early boot problems, it's common to sprinkle printk's
all over the place.  However, on 64-bit powerpc, this can lead to
memory corruption if done too early due to the PACA pointer and
lockdep core not being initialized.

This adds some comments to early_setup() that document when it is
safe to do so in order to save time for whoever has to debug that
stuff next.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
arch/powerpc/kernel/setup_64.c