[PATCH] powerpc: Add udbg-immortal kernel option

[PATCH] powerpc: Add udbg-immortal kernel option

[Benjamin Herrenschmidt]

When debugging early kernel crashes that happen after console_init() and
before a proper console driver takes over, we often have to go hack into
udbg.c to prevent it from unregistering so we can "see" what is
happening. This patch adds a kernel command line option "udbg-immortal"
instead to avoid having to modify the kernel.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

---
Paul: this is not 2.6.17 material

Index: linux-work/arch/powerpc/kernel/udbg.c
===================================================================
--- linux-work.orig/arch/powerpc/kernel/udbg.c	2006-05-31 14:13:59.000000000 +1000
+++ linux-work/arch/powerpc/kernel/udbg.c	2006-05-31 14:48:07.000000000 +1000
@@ -14,6 +14,7 @@
 #include <linux/types.h>
 #include <linux/sched.h>
 #include <linux/console.h>
+#include <linux/init.h>
 #include <asm/processor.h>
 #include <asm/udbg.h>
 
@@ -141,12 +142,14 @@ static int early_console_initialized;
 
 void __init disable_early_printk(void)
 {
-#if 1
 	if (!early_console_initialized)
 		return;
+	if (strstr(saved_command_line, "udbg-immortal")) {
+		printk(KERN_INFO "early console immortal !\n");
+		return;
+	}
 	unregister_console(&udbg_console);
 	early_console_initialized = 0;
-#endif
 }
 
 /* called by setup_system */

Re: [PATCH] powerpc: Add udbg-immortal kernel option

[Olof Johansson]

On Wed, Jun 07, 2006 at 12:06:20PM +1000, Benjamin Herrenschmidt wrote:
>  		return;
> +	if (strstr(saved_command_line, "udbg-immortal")) {
> +		printk(KERN_INFO "early console immortal !\n");
> +		return;
> +	}

So it's YOU who add spaces before punctuation all over arch/powerpc!
Please fix. ;-)


-Olof

Re: [PATCH] powerpc: Add udbg-immortal kernel option

[Benjamin Herrenschmidt]

On Tue, 2006-06-06 at 19:24 -0700, Olof Johansson wrote:
> On Wed, Jun 07, 2006 at 12:06:20PM +1000, Benjamin Herrenschmidt wrote:
> >  		return;
> > +	if (strstr(saved_command_line, "udbg-immortal")) {
> > +		printk(KERN_INFO "early console immortal !\n");
> > +		return;
> > +	}
> 
> So it's YOU who add spaces before punctuation all over arch/powerpc!
> Please fix. ;-)

No way :) Besides, that's how it should be done in french :)

Ben.

Re: [PATCH] powerpc: Add udbg-immortal kernel option

[Arnd Bergmann]

On Wednesday 07 June 2006 06:19, Benjamin Herrenschmidt wrote:
> No way :) Besides, that's how it should be done in french :)
>=20
So you mean, like this?

Index: linux-work/arch/powerpc/kernel/udbg.c
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=2D-- linux-work.orig/arch/powerpc/kernel/udbg.c	2006-05-31 14:13:59.000000=
000 +1000
+++ linux-work/arch/powerpc/kernel/udbg.c	2006-05-31 14:48:07.000000000 +10=
00
@@ -141,12 +142,14 @@ static int early_console_initialized;
=20
 void __init disable_early_printk(void)
 {
=2D#if 1
 	if (!early_console_initialized)
 		return;
+	if (strstr(saved_command_line, "udbg-immortel")) {
+		printk(KERN_INFO "console t=F4t immortel !\n");
+		return;
+	}
 	unregister_console(&udbg_console);
 	early_console_initialized =3D 0;
=2D#endif
 }
=20
 /* called by setup_system */