linux-kernel - Re: [PATCH 4/4] rtc: s3c: enable/disable clocks for alarm

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: Windows password security audit tool. GUI, reports in PDF.

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

Message-id: <55CA9330.9070700@samsung.com>
Date:	Wed, 12 Aug 2015 09:28:32 +0900
From:	Krzysztof Kozlowski <k.kozlowski@...sung.com>
To:	Joonyoung Shim <jy0922.shim@...sung.com>,
	rtc-linux@...glegroups.com
Cc:	linux-kernel@...r.kernel.org, linux-samsung-soc@...r.kernel.org,
	a.zummo@...ertech.it, alexandre.belloni@...e-electrons.com,
	cw00.choi@...sung.com
Subject: Re: [PATCH 4/4] rtc: s3c: enable/disable clocks for alarm

On 11.08.2015 20:28, Joonyoung Shim wrote:
> The clock enable/disable codes for alarm have removed from

What do you mean in this paragraph? The clock code was removing something?

> 'commit 24e1455493da ("drivers/rtc/rtc-s3c.c: delete duplicate clock

Remove the 'apostrophe.

> control")' and the clocks keep disabling even if alarm is set, so alarm
> interrupt can't happen.
...and the clocks are disabled even...


> 
> The s3c_rtc_setaie function can be called several times with that
> enabled argument has same value,
...several times with 'enabled' argument having same value

> so it needs to check whether clocks is
> enabled or not.
s/is/are/

> 
> Signed-off-by: Joonyoung Shim <jy0922.shim@...sung.com>

Please add Cc-stable and fixes tag. To backport the patch probably
you'll have to remove the dependency on previous patches.

> ---
>  drivers/rtc/rtc-s3c.c | 24 ++++++++++++++++++------
>  1 file changed, 18 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/rtc/rtc-s3c.c b/drivers/rtc/rtc-s3c.c
> index abe2a6d..fce078c 100644
> --- a/drivers/rtc/rtc-s3c.c
> +++ b/drivers/rtc/rtc-s3c.c
> @@ -39,6 +39,7 @@ struct s3c_rtc {
>  	void __iomem *base;
>  	struct clk *rtc_clk;
>  	struct clk *rtc_src_clk;
> +	bool clk_enabled;
>  
>  	struct s3c_rtc_data *data;
>  
> @@ -71,9 +72,12 @@ static void s3c_rtc_enable_clk(struct s3c_rtc *info)
>  	unsigned long irq_flags;
>  
>  	spin_lock_irqsave(&info->alarm_clk_lock, irq_flags);
> -	clk_enable(info->rtc_clk);
> -	if (info->data->needs_src_clk)
> -		clk_enable(info->rtc_src_clk);
> +	if (!info->clk_enabled) {
> +		clk_enable(info->rtc_clk);
> +		if (info->data->needs_src_clk)
> +			clk_enable(info->rtc_src_clk);
> +		info->clk_enabled = true;
> +	}
>  	spin_unlock_irqrestore(&info->alarm_clk_lock, irq_flags);
>  }
>  
> @@ -82,9 +86,12 @@ static void s3c_rtc_disable_clk(struct s3c_rtc *info)
>  	unsigned long irq_flags;
>  
>  	spin_lock_irqsave(&info->alarm_clk_lock, irq_flags);
> -	if (info->data->needs_src_clk)
> -		clk_disable(info->rtc_src_clk);
> -	clk_disable(info->rtc_clk);
> +	if (info->clk_enabled) {
> +		if (info->data->needs_src_clk)
> +			clk_disable(info->rtc_src_clk);
> +		clk_disable(info->rtc_clk);
> +		info->clk_enabled = false;
> +	}
>  	spin_unlock_irqrestore(&info->alarm_clk_lock, irq_flags);
>  }
>  
> @@ -128,6 +135,11 @@ static int s3c_rtc_setaie(struct device *dev, unsigned int enabled)
>  
>  	s3c_rtc_disable_clk(info);
>  
> +	if (enabled)
> +		s3c_rtc_enable_clk(info);
> +	else
> +		s3c_rtc_disable_clk(info);
> +
>  	return 0;
>  }

During probe the clk_enabled is false, so the clock won't be disabled at
the end of probe with s3c_rtc_disable_clk(). Maybe previous patch
interferes here so it would work after applying all 4 patches but not
when backporting. The patch in current form looks non-backportable.

Best regards,
KRzysztof
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/