diff options
| author | Sudeep Holla <sudeep.holla@arm.com> | 2015-01-08 09:29:04 +0300 |
|---|---|---|
| committer | Daniel Lezcano <daniel.lezcano@linaro.org> | 2015-01-23 17:05:48 +0300 |
| commit | 194fe6f28e2819d3f50fbed24c3b72f21501dbfa (patch) | |
| tree | e76c25ad91ead6ba5d1caaf462c5862888fa691c /drivers | |
| parent | ec6f34e5b552fb0a52e6aae1a5afbbb1605cc6cc (diff) | |
| download | linux-194fe6f28e2819d3f50fbed24c3b72f21501dbfa.tar.xz | |
drivers: cpuidle: Don't initialize big.LITTLE driver if MCPM is unavailable
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>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/cpuidle/cpuidle-big_little.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/cpuidle/cpuidle-big_little.c b/drivers/cpuidle/cpuidle-big_little.c index e3e225fe6b45..40c34faffe59 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 |