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From:   Sasha Levin <sashal@kernel.org>
To:     linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc:     Srinivas Ramana <sramana@codeaurora.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        linux-arm-msm@vger.kernel.org, Sasha Levin <sashal@kernel.org>
Subject: [PATCH AUTOSEL 4.20 20/77] genirq: Make sure the initial affinity is not empty
Date:   Thu, 14 Feb 2019 21:07:58 -0500
Message-Id: <20190215020855.176727-20-sashal@kernel.org>
In-Reply-To: <20190215020855.176727-1-sashal@kernel.org>
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From: Srinivas Ramana <sramana@codeaurora.org>

[ Upstream commit bddda606ec76550dd63592e32a6e87e7d32583f7 ]

If all CPUs in the irq_default_affinity mask are offline when an interrupt
is initialized then irq_setup_affinity() can set an empty affinity mask for
a newly allocated interrupt.

Fix this by falling back to cpu_online_mask in case the resulting affinity
mask is zero.

Signed-off-by: Srinivas Ramana <sramana@codeaurora.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arm-msm@vger.kernel.org
Link: https://lkml.kernel.org/r/1545312957-8504-1-git-send-email-sramana@codeaurora.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 kernel/irq/manage.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 9dbdccab3b6a..5c0ba5ca5930 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -393,6 +393,9 @@ int irq_setup_affinity(struct irq_desc *desc)
 	}
 
 	cpumask_and(&mask, cpu_online_mask, set);
+	if (cpumask_empty(&mask))
+		cpumask_copy(&mask, cpu_online_mask);
+
 	if (node != NUMA_NO_NODE) {
 		const struct cpumask *nodemask = cpumask_of_node(node);
 
-- 
2.19.1