[PATCH] tracing: Fix TRACING_SUPPORT dependency for PPC32

[Steven Rostedt]

On Tue, 24 Mar 2009, Anton Vorontsov wrote:

> commit 40ada30f9621fbd831ac2437b9a2a399aa ("tracing: clean up menu"),
> despite the "clean up" in its purpose, introduced a behavioural
> change for Kconfig symbols: we no longer able to select tracing
> support on PPC32 (because IRQFLAGS_SUPPORT isn't yet implemented).
> 
> The IRQFLAGS_SUPPORT is not mandatory for most tracers, tracing core
> has a special case for platforms w/o irqflags (which, by the way, has
> become useless as of the commit above).
> 
> Though according to Ingo Molnar, there was periodic build failures on
> weird, unmaintained architectures that had no irqflags-tracing support
> and hence didn't know the raw_irqs_save/restore primitives. Thus we'd
> better not enable irqflags-less tracing for all architectures.
> 
> This patch restores the old behaviour for PPC32, and thus brings the
> tracing back. Other architectures can either add themselves to the
> exception list or (better) implement TRACE_IRQFLAGS_SUPPORT.
> 
> Signed-off-by: Anton Vorontsov <avorontsov at ru.mvista.com>
[..]

> diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
> index ee70841..2246141 100644
> --- a/kernel/trace/Kconfig
> +++ b/kernel/trace/Kconfig
> @@ -63,7 +63,11 @@ config TRACING
>  #
>  config TRACING_SUPPORT
>  	bool
> -	depends on TRACE_IRQFLAGS_SUPPORT
> +	# PPC32 has no irqflags tracing support, but it can use most of the
> +	# tracers anyway, they were tested to build and work. Note that new
> +	# exceptions to this list aren't welcomed, better implement the
> +	# irqflags tracing for your architecture.
> +	depends on TRACE_IRQFLAGS_SUPPORT || PPC32
>  	depends on STACKTRACE_SUPPORT
>  	default y
> 

I'm fine with this.

Acked-by: Steven Rostedt <srostedt at redhat.com>

-- Steve