Re: [PATCH v2] early_printk: consolidate random copies of identicalcode

From: Paul Gortmaker
Date: Thu Mar 07 2013 - 15:21:38 EST


On 13-03-07 02:25 PM, Andrew Morton wrote:
> On Thu, 7 Mar 2013 14:15:54 -0500 Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx> wrote:
>
>> [v2: essentially unchanged since v1, so I've left the acked/reviewed
>> tags. There was a compile fail[1] for a randconfig with EARLY_PRINTK=y
>> and PRINTK=n, because the early_console struct and early_printk calls
>> were nested within an #ifdef CONFIG_PRINTK -- moving that whole block
>> exactly as-is to be outside the #ifdef CONFIG_PRINTK fixes the randconfig
>> and still works for everyday sane configs too.]
>> [1] http://marc.info/?l=linux-next&m=136219350914998&w=2
>
> You did this:
>

[...]

> _
>
> Problem is, that won't fix the various compilation problems we've had.
> See yesterday's lkml thread "linux-next: build failure after merge of
> the final tree (akpm tree related)"

Unless I'm missing something, the easy fix for that is to just
unconditionally have an early_console, i.e. this one line change
on top of the v2 patch:

diff --git a/kernel/printk.c b/kernel/printk.c
index 7664e49..86799bf 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -120,6 +120,7 @@ struct console_cmdline
static struct console_cmdline console_cmdline[MAX_CMDLINECONSOLES];
static int selected_console = -1;
static int preferred_console = -1;
+struct console *early_console;
int console_set_on_cmdline;
EXPORT_SYMBOL(console_set_on_cmdline);

@@ -1718,7 +1719,6 @@ static size_t cont_print_text(char *text, size_t size) { return 0; }
#endif /* CONFIG_PRINTK */

#ifdef CONFIG_EARLY_PRINTK
-struct console *early_console;

void early_vprintk(const char *fmt, va_list ap)
{


Then you don't have to spray any of those ifdefs into the sparc code.
I've build tested the above tweak for sparc32/64 defconfig. Also built
for powerpc (sbc8548) -- note that you can't turn off EARLY_PRINTK
for ppc as it is:

config EARLY_PRINTK
bool
default y

i.e. no help text and no prompting. And the kooky randconfig and a
sane x86 defconfig are still OK too. Unless you see something else
that I'm overlooking, I can send a v3 that incorporates the above
small tweak.

Thanks,
Paul.
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