linux-kernel - [PATCH AUTOSEL for 4.9 100/100] cpuidle: fix broadcast control when broadcast can not be entered

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Message-ID: <20171213015722.6722-75-alexander.levin@verizon.com>
Date:   Wed, 13 Dec 2017 01:57:47 +0000
From:   alexander.levin@...izon.com
To:     "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "stable@...r.kernel.org" <stable@...r.kernel.org>
Cc:     Nicholas Piggin <npiggin@...il.com>,
        "Rafael J . Wysocki" <rafael.j.wysocki@...el.com>,
        alexander.levin@...izon.com
Subject: [PATCH AUTOSEL for 4.9 100/100] cpuidle: fix broadcast control when
 broadcast can not be entered

From: Nicholas Piggin <npiggin@...il.com>

[ Upstream commit f187851b9b4a76952b1158b86434563dd2031103 ]

When failing to enter broadcast timer mode for an idle state that
requires it, a new state is selected that does not require broadcast,
but the broadcast variable remains set. This causes
tick_broadcast_exit to be called despite not having entered broadcast
mode.

This causes the WARN_ON_ONCE(!irqs_disabled()) to trigger in some
cases. It does not appear to cause problems for code today, but seems
to violate the interface so should be fixed.

Signed-off-by: Nicholas Piggin <npiggin@...il.com>
Reviewed-by: Thomas Gleixner <tglx@...utronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
Signed-off-by: Sasha Levin <alexander.levin@...izon.com>
---
 drivers/cpuidle/cpuidle.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index c73207abb5a4..35237c8d5206 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -189,6 +189,7 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv,
 			return -EBUSY;
 		}
 		target_state = &drv->states[index];
+		broadcast = false;
 	}
 
 	/* Take note of the planned idle state. */
-- 
2.11.0