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From: "Yinghai Lu" <yinghai@kernel.org>
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To: "Kumar Gala" <galak@kernel.crashing.org>
Subject: Re: [PATCH 1/1] irq: Maintain user set affinity
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On Tue, Nov 4, 2008 at 8:31 AM, Kumar Gala <galak@kernel.crashing.org> wrote:
> From 819ad3ed4660f4238e053728a8b5aa93d22b13d7 Mon Sep 17 00:00:00 2001
> From: Kumar Gala <galak@kernel.crashing.org>
> Date: Tue, 4 Nov 2008 10:13:53 -0600
> Subject: [PATCH 1/1] irq: Maintain user set affinity
>
> This addresses a regression in that if a user specified an affinity
> for an interrupt that affinity information would get reset between
> a request_irq(), free_irq() and request_irq() for the same irq.
>
> On example of this is bringing up an ethernet interface, taking
> it down and bringing it back up again.
>
> Instead of always using the irq_default_affinity we use the
> previous setting of the IRQs affinity with the assumption that
> at boot the IRQs affinity will be set to irq_default_affinity.

why ?, the default_affinity is expected behavior...

for example: when MSI is used, second driver could get same irq if
first driver is unloaded.

YH