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Date: Wed, 24 Oct 2012 22:03:59 +0200
From: Ingo Molnar <mingo@kernel.org>
To: Andi Kleen <andi@firstfloor.org>
Cc: Zheng <zheng.z.yan@intel.com>, Peter Zijlstra <a.p.zijlstra@chello.nl>,
        linux-kernel@vger.kernel.org
Subject: Re: [bug] perf_event_intel_uncore.c build warnings on allnoconfig
Message-ID: <20121024200359.GB25643@gmail.com>
References: <20121024072901.GA25890@gmail.com>
 <m2y5ivrdeu.fsf@firstfloor.org>
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* Andi Kleen <andi@firstfloor.org> wrote:

> Ingo Molnar <mingo@kernel.org> writes:
> 
> > FYI, on a 'make allnoconfig' x86_64 kernel I get a stream of 
> > warnings:
> >
> >  arch/x86/kernel/cpu/perf_event_intel_uncore.c: In function ???snbep_uncore_pci_disable_box???:
> >  arch/x86/kernel/cpu/perf_event_intel_uncore.c:124:9: warning: ???config??? is used uninitialized in this function [-Wuninitialized]
> >  arch/x86/kernel/cpu/perf_event_intel_uncore.c: In function ???snbep_uncore_pci_enable_box???:
> >  arch/x86/kernel/cpu/perf_event_intel_uncore.c:135:9: warning: ???config??? is used uninitialized in this function [-Wuninitialized]
> >  arch/x86/kernel/cpu/perf_event_intel_uncore.c: In function ???snbep_uncore_pci_read_counter???:
> >  arch/x86/kernel/cpu/perf_event_intel_uncore.c:164:2: warning: ???count??? is used uninitialized in this function [-Wuninitialized]
> >
> > Please fix this - if pci_read_config_dword() returns an error it 
> > should be handled - that will fix these warnings as well.
> 
> Can it even return an error on x86? I don't know of any 
> existing mechanism for this, short of a machine check.

It will return an error on !CONFIG_PCI at least.

Thanks,

	Ingo