On Mon, 2008-06-23 at 18:52 +0800, Chen, Huacai wrote:
> From: Huacai Chen <huacai.chen@xxxxxxxxx>
>
> 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@xxxxxxxxx>
> Acked-by: Pavel Machek <pavel@xxxxxxx>
> ---
> diff --git a/drivers/acpi/sleep/proc.c b/drivers/acpi/sleep/proc.c
> index 224c57c..c9fdf7b 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);
> + }
this is OK.
> /* enable the rtc alarm interrupt */
> rtc_control |= RTC_AIE;
> CMOS_WRITE(rtc_control, RTC_CONTROL);
> ---
> This is for Linux 2.6.26-rc7.
> --
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