From: Daniel Lezcano <daniel.lezcano@linaro.org>
To: rjw@rjwysocki.net
Cc: Sudeep.Holla@arm.com, Lorenzo.Pieralisi@arm.com,
linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] drivers: cpuidle: Don't initialize big.LITTLE driver if MCPM is unavailable
Date: Sun, 25 Jan 2015 21:53:47 +0100 [thread overview]
Message-ID: <1422219227-25808-1-git-send-email-daniel.lezcano@linaro.org> (raw)
In-Reply-To: <54C5002C.4050600@linaro.org>
From: Sudeep Holla <sudeep.holla@arm.com>
If big.LITTLE driver is initialized even when MCPM is unavailable,
we get the below warning the first time cpu tries to enter deeper
C-states.
------------[ cut here ]------------
WARNING: CPU: 4 PID: 0 at kernel/arch/arm/common/mcpm_entry.c:130 mcpm_cpu_suspend+0x6d/0x74()
Modules linked in:
CPU: 4 PID: 0 Comm: swapper/4 Not tainted 3.19.0-rc3-00007-gaf5a2cb1ad5c-dirty #11
Hardware name: ARM-Versatile Express
[<c0013fa5>] (unwind_backtrace) from [<c001084d>] (show_stack+0x11/0x14)
[<c001084d>] (show_stack) from [<c04fe7f1>] (dump_stack+0x6d/0x78)
[<c04fe7f1>] (dump_stack) from [<c0020645>] (warn_slowpath_common+0x69/0x90)
[<c0020645>] (warn_slowpath_common) from [<c00206db>] (warn_slowpath_null+0x17/0x1c)
[<c00206db>] (warn_slowpath_null) from [<c001cbdd>] (mcpm_cpu_suspend+0x6d/0x74)
[<c001cbdd>] (mcpm_cpu_suspend) from [<c03c6919>] (bl_powerdown_finisher+0x21/0x24)
[<c03c6919>] (bl_powerdown_finisher) from [<c001218d>] (cpu_suspend_abort+0x1/0x14)
[<c001218d>] (cpu_suspend_abort) from [<00000000>] ( (null))
---[ end trace d098e3fd00000008 ]---
This patch fixes the issue by checking for the availability of MCPM
before initializing the big.LITTLE cpuidle driver
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
---
drivers/cpuidle/cpuidle-big_little.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/cpuidle/cpuidle-big_little.c b/drivers/cpuidle/cpuidle-big_little.c
index e3e225f..40c34fa 100644
--- a/drivers/cpuidle/cpuidle-big_little.c
+++ b/drivers/cpuidle/cpuidle-big_little.c
@@ -182,6 +182,10 @@ static int __init bl_idle_init(void)
*/
if (!of_match_node(compatible_machine_match, root))
return -ENODEV;
+
+ if (!mcpm_is_available())
+ return -EUNATCH;
+
/*
* For now the differentiation between little and big cores
* is based on the part number. A7 cores are considered little
--
1.9.1
next prev parent reply other threads:[~2015-01-25 20:53 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-25 14:39 [GIT PULL] : cpuidle-big.little fix when mcpm is not available Daniel Lezcano
2015-01-25 20:53 ` Daniel Lezcano [this message]
2015-01-26 0:30 ` Rafael J. Wysocki
-- strict thread matches above, loose matches on Subject: below --
2015-01-08 6:29 [PATCH] drivers: cpuidle: don't initialize big.LITTLE driver if MCPM is unavailable Sudeep Holla
2015-01-08 6:29 ` Sudeep Holla
2015-01-08 8:53 ` Daniel Lezcano
2015-01-08 8:53 ` Daniel Lezcano
2015-01-08 9:16 ` Sudeep Holla
2015-01-08 9:16 ` Sudeep Holla
2015-01-08 10:02 ` Daniel Lezcano
2015-01-08 10:02 ` Daniel Lezcano
2015-01-08 10:31 ` Sudeep Holla
2015-01-08 10:31 ` Sudeep Holla
2015-01-08 11:11 ` Daniel Lezcano
2015-01-08 11:11 ` Daniel Lezcano
2015-01-08 12:29 ` Lorenzo Pieralisi
2015-01-08 12:29 ` Lorenzo Pieralisi
2015-01-08 14:01 ` Daniel Lezcano
2015-01-08 14:01 ` Daniel Lezcano
2015-01-08 14:46 ` Lorenzo Pieralisi
2015-01-08 14:46 ` Lorenzo Pieralisi
2015-01-08 20:27 ` Kevin Hilman
2015-01-08 20:27 ` Kevin Hilman
2015-01-08 20:51 ` Daniel Lezcano
2015-01-08 20:51 ` Daniel Lezcano
2015-01-09 17:34 ` Kevin Hilman
2015-01-09 17:34 ` Kevin Hilman
2015-01-09 4:58 ` Sudeep Holla
2015-01-09 4:58 ` Sudeep Holla
2015-01-09 5:01 ` Sudeep Holla
2015-01-09 5:01 ` Sudeep Holla
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