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rtc/hctosys: only claim the RTC provided the system time if it did

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Without this patch /sys/class/rtc/$CONFIG_RTC_HCTOSYS_DEVICE/hctosys
contains a 1 (meaning "This rtc was used to initialize the system clock")
even if reading the time at bootup failed.

Moreover change error handling in rtc_hctosys() to use goto and so reduce
the indention level.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Paul Gortmaker <p_gortmaker@yahoo.com>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Uwe Kleine-König 2010-03-10 15:20:35 -08:00 committed by Linus Torvalds
parent 019b4d123a
commit d0ab4a4d50
3 changed files with 45 additions and 29 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

63
drivers/rtc/hctosys.c
View File

@ -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;
tv.tv_nsec = NSEC_PER_SEC >> 1;
rtc_tm_to_time(&tm, &tv.tv_sec);
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);
}
else
dev_err(rtc->dev.parent,
"hctosys: invalid date/time\n");
}
else
if (err) {
dev_err(rtc->dev.parent,
"hctosys: unable to read the hardware clock\n");
goto err_read;
}
err = rtc_valid_tm(&tm);
if (err) {
dev_err(rtc->dev.parent,
"hctosys: invalid date/time\n");
goto err_invalid;
}
rtc_tm_to_time(&tm, &tv.tv_sec);
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);

5
drivers/rtc/rtc-sysfs.c
View File

@ -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

6
include/linux/rtc.h
View File

@ -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_ */