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| author | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2008-05-07 10:00:56 +1000 |
|---|---|---|
| committer | Paul Mackerras <paulus@samba.org> | 2008-05-09 20:22:58 +1000 |
| commit | 24d9649574fbe591fdfa6b00893d4096f513e539 (patch) | |
| tree | de6b2a4b4e1d7754d4100404b4d74574be0a608e /arch/powerpc | |
| parent | 1b70c5a6491dd02263e6d104b72d9b536f987021 (diff) | |
| download | kernel_samsung_tuna-24d9649574fbe591fdfa6b00893d4096f513e539.zip kernel_samsung_tuna-24d9649574fbe591fdfa6b00893d4096f513e539.tar.gz kernel_samsung_tuna-24d9649574fbe591fdfa6b00893d4096f513e539.tar.bz2 | |
[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>
Diffstat (limited to 'arch/powerpc')
| -rw-r--r-- | arch/powerpc/kernel/setup_64.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c index 25e3fd8..f2cd82e 100644 --- a/arch/powerpc/kernel/setup_64.c +++ b/arch/powerpc/kernel/setup_64.c @@ -170,6 +170,8 @@ void __init setup_paca(int cpu) void __init early_setup(unsigned long dt_ptr) { + /* -------- printk is _NOT_ safe to use here ! ------- */ + /* Fill in any unititialised pacas */ initialise_pacas(); @@ -185,6 +187,8 @@ void __init early_setup(unsigned long dt_ptr) /* Initialize lockdep early or else spinlocks will blow */ lockdep_init(); + /* -------- printk is now safe to use ------- */ + DBG(" -> early_setup(), dt_ptr: 0x%lx\n", dt_ptr); /* |