linux-kernel - Re: [PATCH] mfd: arizona: Use suspend_noirq inplace of suspend

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <20160831124432.GH9415@dell>
Date:   Wed, 31 Aug 2016 13:44:32 +0100
From:   Lee Jones <lee.jones@...aro.org>
To:     Charles Keepax <ckeepax@...nsource.wolfsonmicro.com>
Cc:     linux-kernel@...r.kernel.org, patches@...nsource.wolfsonmicro.com
Subject: Re: [PATCH] mfd: arizona: Use suspend_noirq inplace of suspend_late

On Tue, 30 Aug 2016, Charles Keepax wrote:

> As runtime PM doesn't function whilst processing system suspend/resume
> operations and the Arizona IRQ handlers need runtime PM to function
> we must disable IRQs during these operations. Whilst this is
> already done in the driver we are using suspend/suspend_late and
> resume/resume_noirq to do so which has two problems. Firstly, as
> suspend_late is before suspend_noirq that means we still have a
> small window where an IRQ can cause issues.  Secondly, if another
> suspend_late handler fails after ours has run then (as resume_noirq
> will not run) we will make unbalanced calls to enable_irq.
> 
> This is all simply fixed by using the suspend_noirq callback rather
> than suspend_late. Whilst we are doing this tidy the code up a little,
> and use the appropriate helper macros.
> 
> Signed-off-by: Charles Keepax <ckeepax@...nsource.wolfsonmicro.com>
> ---
>  drivers/mfd/arizona-core.c | 10 ++++------
>  1 file changed, 4 insertions(+), 6 deletions(-)

Applied, thanks.

> diff --git a/drivers/mfd/arizona-core.c b/drivers/mfd/arizona-core.c
> index 34a2c26..fe2277d 100644
> --- a/drivers/mfd/arizona-core.c
> +++ b/drivers/mfd/arizona-core.c
> @@ -735,7 +735,7 @@ static int arizona_suspend(struct device *dev)
>  	return 0;
>  }
>  
> -static int arizona_suspend_late(struct device *dev)
> +static int arizona_suspend_noirq(struct device *dev)
>  {
>  	struct arizona *arizona = dev_get_drvdata(dev);
>  
> @@ -759,7 +759,7 @@ static int arizona_resume(struct device *dev)
>  {
>  	struct arizona *arizona = dev_get_drvdata(dev);
>  
> -	dev_dbg(arizona->dev, "Late resume, reenabling IRQ\n");
> +	dev_dbg(arizona->dev, "Resume, reenabling IRQ\n");
>  	enable_irq(arizona->irq);
>  
>  	return 0;
> @@ -771,10 +771,8 @@ const struct dev_pm_ops arizona_pm_ops = {
>  			   arizona_runtime_resume,
>  			   NULL)
>  	SET_SYSTEM_SLEEP_PM_OPS(arizona_suspend, arizona_resume)
> -#ifdef CONFIG_PM_SLEEP
> -	.suspend_late = arizona_suspend_late,
> -	.resume_noirq = arizona_resume_noirq,
> -#endif
> +	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(arizona_suspend_noirq,
> +				      arizona_resume_noirq)
>  };
>  EXPORT_SYMBOL_GPL(arizona_pm_ops);
>  

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog