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authorHuacai Chen <huacai.chen@intel.com>2008-07-04 09:59:31 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-07-04 10:40:05 -0700
commitcce3ce89c1abde1298dd0e769ab9c14ea95d7384 (patch)
treefc1ab92f843d28ba4aff86e5c6e0ea225868478f
parent471d47e3223311d2638755717f97dc9a298f6dc9 (diff)
rtc: fix CMOS time error after writing /proc/acpi/alarm
When writing /proc/acpi/alarm in adjust mode, e.g. echo "+0000-00-00 00:00:15" >/proc/acpi/alarm The "century" field should be read and added to "year" field before writing, otherwise the CMOS time will go back to 2000 years ago, e.g. # cat /proc/acpi/alarm 0008-06-21 11:38:46 Then the system time may be reset to the date of manufacture after rebooting. This patch fixed this issue. Signed-off-by: Huacai Chen <huacai.chen@intel.com> Acked-by: Pavel Machek <pavel@suse.cz> Acked-by: Zhao Yakui <yakui.zhao@intel.com> Acked-by: Alessandro Zummo <a.zummo@towertech.it> Acked-by: Len Brown <lenb@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--drivers/acpi/sleep/proc.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/acpi/sleep/proc.c b/drivers/acpi/sleep/proc.c
index 224c57c0338..4ebbba2b6b1 100644
--- a/drivers/acpi/sleep/proc.c
+++ b/drivers/acpi/sleep/proc.c
@@ -315,8 +315,11 @@ acpi_system_write_alarm(struct file *file,
cmos_bcd_write(day, acpi_gbl_FADT.day_alarm, rtc_control);
if (acpi_gbl_FADT.month_alarm)
cmos_bcd_write(mo, acpi_gbl_FADT.month_alarm, rtc_control);
- if (acpi_gbl_FADT.century)
+ if (acpi_gbl_FADT.century) {
+ if (adjust)
+ yr += cmos_bcd_read(acpi_gbl_FADT.century, rtc_control) * 100;
cmos_bcd_write(yr / 100, acpi_gbl_FADT.century, rtc_control);
+ }
/* enable the rtc alarm interrupt */
rtc_control |= RTC_AIE;
CMOS_WRITE(rtc_control, RTC_CONTROL);