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From: Greg KH <greg@kroah.com>
To: Stefan Bader <stefan.bader@canonical.com>
Cc: stable@kernel.org, Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@elte.hu>, Yinghai Lu <yinghai@kernel.org>,
	linux-kernel@vger.kernel.org, "H. Peter Anvin" <hpa@zytor.com>
Subject: Re: [stable] [PATCH] x86: Reserve FIRST_DEVICE_VECTOR in used_vectors bitmap
Date: Fri, 10 Oct 2008 13:18:05 -0700	[thread overview]
Message-ID: <20081010201805.GC32164@kroah.com> (raw)
In-Reply-To: <48EFB4B2.2020508@canonical.com>

On Fri, Oct 10, 2008 at 04:01:54PM -0400, Stefan Bader wrote:
> Affected: 2.6.24-2.6.27
> 
> Someone from the community found out, that after repeatedly unloading and
> loading a device driver that uses MSI IRQs, the system eventually assigned
> the vector initially reserved for IRQ0 to the device driver.
> 
> The reason for this is, that although IRQ0 is tied to the FIRST_DEVICE_VECTOR
> when declaring the irq_vector table, the corresponding bit in the used_vectors
> map is not set. So, if vectors are released and assigned often enough, the
> vector will get assigned to another interrupt. This happens more often with
> MSI interrupts as those are exclusively using a vector.

Is there a problem with being assigned to IRQ0 in situations like this?

thanks,

greg k-h

  parent reply	other threads:[~2008-10-10 20:21 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-10-10 20:01 [PATCH] x86: Reserve FIRST_DEVICE_VECTOR in used_vectors bitmap Stefan Bader
2008-10-10 20:16 ` [stable] " Greg KH
2008-10-10 20:23   ` Ingo Molnar
2008-10-10 20:29     ` Greg KH
2008-10-10 20:36       ` Stefan Bader
2008-10-10 20:41         ` Greg KH
2008-10-10 20:16 ` Greg KH
2008-10-10 20:22   ` Stefan Bader
2008-10-10 20:18 ` Greg KH [this message]
2008-10-10 20:24   ` Stefan Bader
2008-10-10 20:35   ` H. Peter Anvin
2008-10-10 20:41     ` Greg KH
2008-10-10 20:50       ` Alan Cox
2008-10-10 21:12         ` Greg KH
2008-10-10 21:49           ` Alan Cox
2008-10-10 22:09             ` Greg KH

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