Re: [PATCH] cpuidle: coupled: Enable interrupts when early returning on invalid driver
From: Daniel Lezcano
Date: Thu Jul 24 2014 - 05:35:14 EST
On 07/24/2014 11:26 AM, Krzysztof Kozlowski wrote:
cpuidle_enter_state is expected to return with interrupts enabled.
However cpuidle_enter_state_coupled returned with interrupts disabled if
the cpuidle driver was registered without mask of coupled cpus.
Hi Krzysztof,
may be your patch is right but I would like to clarify one thing. This
is the cpuidle driver for exynos. AFAICT, the coupled states shouldn't
be enabled for this driver, so how did you face this issue ?
This could be observed as a warning:
[ 1.613132] ------------[ cut here ]------------
[ 1.613244] WARNING: CPU: 0 PID: 0 at kernel/sched/idle.c:175 cpu_idle_loop+0x2dc/0x6d0()
[ 1.620268] Modules linked in:
[ 1.623311] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.16.0-rc4-00102-g7669ccdbf8af-dirty #81
[ 1.623619] dwmmc_exynos 12510000.mshc: 1 slots initialized
[ 1.624890] logger: created 256K log 'log_main'
[ 1.625483] logger: created 256K log 'log_events'
[ 1.626084] logger: created 256K log 'log_radio'
[ 1.626699] logger: created 256K log 'log_system'
[ 1.655960] [<c00167cc>] (unwind_backtrace) from [<c0012c28>] (show_stack+0x10/0x14)
[ 1.663679] [<c0012c28>] (show_stack) from [<c050ab00>] (dump_stack+0x70/0xbc)
[ 1.670883] [<c050ab00>] (dump_stack) from [<c0023ac8>] (warn_slowpath_common+0x68/0x8c)
[ 1.678954] [<c0023ac8>] (warn_slowpath_common) from [<c0023b08>] (warn_slowpath_null+0x1c/0x24)
[ 1.687720] [<c0023b08>] (warn_slowpath_null) from [<c006ddd4>] (cpu_idle_loop+0x2dc/0x6d0)
[ 1.696052] [<c006ddd4>] (cpu_idle_loop) from [<c006e1d4>] (cpupri_find+0x0/0xd4)
[ 1.703518] [<c006e1d4>] (cpupri_find) from [<c07cdd14>] (processor_id+0x0/0x2c)
[ 1.710917] ---[ end trace a85327313857296e ]---
Enable the interrupts also when early returning from
cpuidle_enter_state_coupled due to invalid coupled configuration.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@xxxxxxxxxxx>
Fixes: 4126c0197bc8 ("cpuidle: add support for states that affect multiple cpus")
Cc: <stable@xxxxxxxxxxxxxxx>
---
drivers/cpuidle/coupled.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/cpuidle/coupled.c b/drivers/cpuidle/coupled.c
index 73fe2f8d7f96..2b57c267e855 100644
--- a/drivers/cpuidle/coupled.c
+++ b/drivers/cpuidle/coupled.c
@@ -463,8 +463,10 @@ int cpuidle_enter_state_coupled(struct cpuidle_device *dev,
struct cpuidle_coupled *coupled = dev->coupled;
int w;
- if (!coupled)
+ if (!coupled) {
+ local_irq_enable();
return -EINVAL;
+ }
while (coupled->prevent) {
cpuidle_coupled_clear_pokes(dev->cpu);
--
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