linux-kernel - Re: [rtc-linux] [PATCH RESEND] rtc/hctosys: only claim the RTC provided the system time if it did

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Date:	Thu, 11 Feb 2010 11:57:00 +0100
From:	Alessandro Zummo <a.zummo@...ertech.it>
To:	rtc-linux@...glegroups.com
Cc:	u.kleine-koenig@...gutronix.de,
	Paul Gortmaker <p_gortmaker@...oo.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	linux-kernel@...r.kernel.org
Subject: Re: [rtc-linux] [PATCH RESEND] rtc/hctosys: only claim the RTC
 provided  the system time if it did

On Thu, 11 Feb 2010 11:52:29 +0100
Uwe Kleine-König <u.kleine-koenig@...gutronix.de> wrote:


> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@...gutronix.de>
> ---
> Hello,
> 
> this time the patch is complete.
> 
> What do you think about it?

 looks nice but I'll have to give a deeper look.
 will probably queue for the next merge window
 

> 
> Best regards
> Uwe
> 
>  drivers/rtc/hctosys.c   |   59 +++++++++++++++++++++++++++--------------------
>  drivers/rtc/rtc-sysfs.c |    5 ++-
>  include/linux/rtc.h     |    6 ++++
>  3 files changed, 43 insertions(+), 27 deletions(-)
> 
> diff --git a/drivers/rtc/hctosys.c b/drivers/rtc/hctosys.c
> index 33c0e98..bc90b09 100644
> --- a/drivers/rtc/hctosys.c
> +++ b/drivers/rtc/hctosys.c
> @@ -22,48 +22,57 @@
>   * the best guess is to add 0.5s.
>   */
>  
> +int rtc_hctosys_ret = -ENODEV;
> +
>  static int __init rtc_hctosys(void)
>  {
> -	int err;
> +	int err = -ENODEV;
>  	struct rtc_time tm;
> +	struct timespec tv = {
> +		.tv_nsec = NSEC_PER_SEC >> 1,
> +	};
>  	struct rtc_device *rtc = rtc_class_open(CONFIG_RTC_HCTOSYS_DEVICE);
>  
>  	if (rtc == NULL) {
> -		printk("%s: unable to open rtc device (%s)\n",
> +		pr_err("%s: unable to open rtc device (%s)\n",
>  			__FILE__, CONFIG_RTC_HCTOSYS_DEVICE);
> -		return -ENODEV;
> +		goto err_open;
>  	}
>  
>  	err = rtc_read_time(rtc, &tm);
> -	if (err == 0) {
> -		err = rtc_valid_tm(&tm);
> -		if (err == 0) {
> -			struct timespec tv;
> +	if (err) {
> +		dev_err(rtc->dev.parent,
> +			"hctosys: unable to read the hardware clock\n");
> +		goto err_read;
>  
> -			tv.tv_nsec = NSEC_PER_SEC >> 1;
> +	}
>  
> -			rtc_tm_to_time(&tm, &tv.tv_sec);
> +	err = rtc_valid_tm(&tm);
> +	if (err) {
> +		dev_err(rtc->dev.parent,
> +			"hctosys: invalid date/time\n");
> +		goto err_invalid;
> +	}
>  
> -			do_settimeofday(&tv);
> +	rtc_tm_to_time(&tm, &tv.tv_sec);
>  
> -			dev_info(rtc->dev.parent,
> -				"setting system clock to "
> -				"%d-%02d-%02d %02d:%02d:%02d UTC (%u)\n",
> -				tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
> -				tm.tm_hour, tm.tm_min, tm.tm_sec,
> -				(unsigned int) tv.tv_sec);
> -		}
> -		else
> -			dev_err(rtc->dev.parent,
> -				"hctosys: invalid date/time\n");
> -	}
> -	else
> -		dev_err(rtc->dev.parent,
> -			"hctosys: unable to read the hardware clock\n");
> +	do_settimeofday(&tv);
>  
> +	dev_info(rtc->dev.parent,
> +		"setting system clock to "
> +		"%d-%02d-%02d %02d:%02d:%02d UTC (%u)\n",
> +		tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
> +		tm.tm_hour, tm.tm_min, tm.tm_sec,
> +		(unsigned int) tv.tv_sec);
> +
> +err_invalid:
> +err_read:
>  	rtc_class_close(rtc);
>  
> -	return 0;
> +err_open:
> +	rtc_hctosys_ret = err;
> +
> +	return err;
>  }
>  
>  late_initcall(rtc_hctosys);
> diff --git a/drivers/rtc/rtc-sysfs.c b/drivers/rtc/rtc-sysfs.c
> index 7dd23a6..380083c 100644
> --- a/drivers/rtc/rtc-sysfs.c
> +++ b/drivers/rtc/rtc-sysfs.c
> @@ -107,8 +107,9 @@ rtc_sysfs_show_hctosys(struct device *dev, struct device_attribute *attr,
>  		char *buf)
>  {
>  #ifdef CONFIG_RTC_HCTOSYS_DEVICE
> -	if (strcmp(dev_name(&to_rtc_device(dev)->dev),
> -		   CONFIG_RTC_HCTOSYS_DEVICE) == 0)
> +	if (rtc_hctosys_ret == 0 &&
> +			strcmp(dev_name(&to_rtc_device(dev)->dev),
> +				CONFIG_RTC_HCTOSYS_DEVICE) == 0)
>  		return sprintf(buf, "1\n");
>  	else
>  #endif
> diff --git a/include/linux/rtc.h b/include/linux/rtc.h
> index 60f88a7..14dbc83 100644
> --- a/include/linux/rtc.h
> +++ b/include/linux/rtc.h
> @@ -238,6 +238,12 @@ static inline bool is_leap_year(unsigned int year)
>  	return (!(year % 4) && (year % 100)) || !(year % 400);
>  }
>  
> +#ifdef CONFIG_RTC_HCTOSYS
> +extern int rtc_hctosys_ret;
> +#else
> +#define rtc_hctosys_ret -ENODEV
> +#endif
> +
>  #endif /* __KERNEL__ */
>  
>  #endif /* _LINUX_RTC_H_ */
> -- 
> 1.6.6
> 
> -- 
> You received this message because you are subscribed to "rtc-linux".
> Membership options at http://groups.google.com/group/rtc-linux .
> Please read http://groups.google.com/group/rtc-linux/web/checklist
> before submitting a driver.


-- 

 Best regards,

 Alessandro Zummo,
  Tower Technologies - Torino, Italy

  http://www.towertech.it

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