[PATCH 1/1] irq: Maintain user set affinity

[Kumar Gala]

>From 819ad3ed4660f4238e053728a8b5aa93d22b13d7 Mon Sep 17 00:00:00 2001
From: Kumar Gala <galak at 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.

Signed-off-by: Kumar Gala <galak at kernel.crashing.org>
---
 kernel/irq/manage.c |    7 +++++--
 1 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index c498a1b..ea7d11b 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -115,9 +115,12 @@ int irq_select_affinity(unsigned int irq)
 	if (!irq_can_set_affinity(irq))
 		return 0;

-	cpus_and(mask, cpu_online_map, irq_default_affinity);
-
 	desc = irq_to_desc(irq);
+
+	mask = desc->affinity;
+
+	cpus_and(mask, cpu_online_map, mask);
+
 	desc->affinity = mask;
 	desc->chip->set_affinity(irq, mask);

-- 
1.5.5.1