[PATCH] no console disabling during suspend stage

[PATCH] no console disabling during suspend stage

[Rodolfo Giometti]

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Hello,

here a little patch to avoid disabling console during suspend stage
while we are debugging kernel.

Ciao,

Rodolfo

Signed-off-by: Rodolfo Giometti <giometti@linux.it>

-- 

GNU/Linux Solutions                  e-mail:    giometti@enneenne.com
Linux Device Driver                             giometti@gnudd.com
Embedded Systems                     		giometti@linux.it
UNIX programming                     phone:     +39 349 2432127

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--- kernel/power/main.c	2006-07-19 10:54:11.000000000 +0200
+++ kernel/power/main.c.new	2006-07-18 19:38:41.000000000 +0200
@@ -86,7 +86,9 @@
 			goto Thaw;
 	}
 
+#ifndef CONFIG_DEBUG_KERNEL
 	suspend_console();
+#endif
 	if ((error = device_suspend(PMSG_SUSPEND))) {
 		printk(KERN_ERR "Some devices failed to suspend\n");
 		goto Finish;

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Re: [PATCH] no console disabling during suspend stage

[Andrew Morton]

On Wed, 19 Jul 2006 11:16:00 +0200
Rodolfo Giometti <giometti@linux.it> wrote:

> here a little patch to avoid disabling console during suspend stage
> while we are debugging kernel.
> 
> ...
>
> --- kernel/power/main.c	2006-07-19 10:54:11.000000000 +0200
> +++ kernel/power/main.c.new	2006-07-18 19:38:41.000000000 +0200
> @@ -86,7 +86,9 @@
>  			goto Thaw;
>  	}
>  
> +#ifndef CONFIG_DEBUG_KERNEL
>  	suspend_console();
> +#endif

CONFIG_DEBUG_KERNEL is not really the appropriate thing to use here - it's
more a user-interface/Kconfig level thing.

Can you please describe the problems which suspend_console() are causing?

Some runtime knob might be more appropriate.  Perhaps /sys/power/debug?

If the suspend_console() call is to be disabled then you'll want to disable
the matching resume_console() call too.

printk.c needs sem2mutex conversion.

The console_suspended/secondary_console_sem handling is racy.  Bad Linus. 
But as we're running on a single CPU and all other tasks are frozen it
doesn't matter.