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Date: Fri, 23 Aug 2013 09:30:52 +0200
From: Ingo Molnar <mingo@kernel.org>
To: Liu Ping Fan <kernelfans@gmail.com>
Cc: x86@kernel.org, linux-kernel@vger.kernel.org,
        Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>,
        "H. Peter Anvin" <hpa@zytor.com>, Kevin Hao <haokexin@gmail.com>
Subject: Re: [PATCH] x86: ioapic needs check attr when programmed more than
 once
Message-ID: <20130823073052.GA25533@gmail.com>
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* Liu Ping Fan <kernelfans@gmail.com> wrote:

> When programming ioapic pinX more than once, current code
> does not check whether the later attr (trigger&polarity) is the
> same as the former or not. This causes a broken semantic.
> 
> Fix it by reporting -EBUSY, when attr is different.

Was this observed in real life somehow, and if yes, what is 
the before/after behavior?

Thanks,

	Ingo