Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1724773 > unrolled thread

[PATCH] cpuidle: fix broadcast control when broadcast can not be entered

Started byNicholas Piggin <npiggin@gmail.com>
First post2017-09-01 06:40 +0200
Last post2017-09-01 09:50 +0200
Articles 2 — 2 participants

Back to article view | Back to linux.kernel


Contents

  [PATCH] cpuidle: fix broadcast control when broadcast can not be entered Nicholas Piggin <npiggin@gmail.com> - 2017-09-01 06:40 +0200
    Re: [PATCH] cpuidle: fix broadcast control when broadcast can not  be entered Thomas Gleixner <tglx@linutronix.de> - 2017-09-01 09:50 +0200

#1724773 — [PATCH] cpuidle: fix broadcast control when broadcast can not be entered

FromNicholas Piggin <npiggin@gmail.com>
Date2017-09-01 06:40 +0200
Subject[PATCH] cpuidle: fix broadcast control when broadcast can not be entered
Message-ID<ukLUl-7eV-3@gated-at.bofh.it>
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@gmail.com>
---
 drivers/cpuidle/cpuidle.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index 60bb64f4329d..4453e27f855e 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -208,6 +208,7 @@ 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. */
-- 
2.13.3

[toc] | [next] | [standalone]


#1724843 — Re: [PATCH] cpuidle: fix broadcast control when broadcast can not be entered

FromThomas Gleixner <tglx@linutronix.de>
Date2017-09-01 09:50 +0200
SubjectRe: [PATCH] cpuidle: fix broadcast control when broadcast can not be entered
Message-ID<ukOSd-Pw-9@gated-at.bofh.it>
In reply to#1724773
On Fri, 1 Sep 2017, Nicholas Piggin wrote:

> 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@gmail.com>

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>

> ---
>  drivers/cpuidle/cpuidle.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
> index 60bb64f4329d..4453e27f855e 100644
> --- a/drivers/cpuidle/cpuidle.c
> +++ b/drivers/cpuidle/cpuidle.c
> @@ -208,6 +208,7 @@ 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. */
> -- 
> 2.13.3
> 
> 

[toc] | [prev] | [standalone]


Back to top | Article view | linux.kernel


csiph-web