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authorMark Lord <lkml@rtr.ca>2008-12-09 10:46:30 -0500
committerLen Brown <len.brown@intel.com>2008-12-10 00:29:35 -0500
commit48452e5f99ab35d643df0463b6ad11aea8ea7bdc (patch)
tree9d5418951b0064f231d1df81f96b1ba624e46f99
parent437f2f91d6597c67662f847d9ed4c99cb3c440cd (diff)
/proc/acpi/alarm: handle day-of-month wraparound on readback
Fix month wrap issue with readback from /proc/acpi/alarm This bug has been around *forever*. $ echo '2008-12-01 10:36:20' > /proc/acpi/alarm $ cat /proc/acpi/alarm 2008-11-01 10:36:20 Note how the readback above shows the month incorrectly when the alarm is set in the *next* calendar month. But with this patch applied, it shows the correct month (12). Signed-off-by: Mark Lord <mlord@pobox.com> Signed-off-by: Len Brown <len.brown@intel.com>
-rw-r--r--drivers/acpi/sleep/proc.c53
1 files changed, 32 insertions, 21 deletions
diff --git a/drivers/acpi/sleep/proc.c b/drivers/acpi/sleep/proc.c
index 4dbc2271acf5..232d4b64140b 100644
--- a/drivers/acpi/sleep/proc.c
+++ b/drivers/acpi/sleep/proc.c
@@ -84,12 +84,15 @@ acpi_system_write_sleep(struct file *file,
#define HAVE_ACPI_LEGACY_ALARM
#endif
+static u32 cmos_bcd_read(int offset, int rtc_control);
+
#ifdef HAVE_ACPI_LEGACY_ALARM
static int acpi_system_alarm_seq_show(struct seq_file *seq, void *offset)
{
u32 sec, min, hr;
u32 day, mo, yr, cent = 0;
+ u32 today = 0;
unsigned char rtc_control = 0;
unsigned long flags;
@@ -97,38 +100,32 @@ static int acpi_system_alarm_seq_show(struct seq_file *seq, void *offset)
spin_lock_irqsave(&rtc_lock, flags);
- sec = CMOS_READ(RTC_SECONDS_ALARM);
- min = CMOS_READ(RTC_MINUTES_ALARM);
- hr = CMOS_READ(RTC_HOURS_ALARM);
rtc_control = CMOS_READ(RTC_CONTROL);
+ sec = cmos_bcd_read(RTC_SECONDS_ALARM, rtc_control);
+ min = cmos_bcd_read(RTC_MINUTES_ALARM, rtc_control);
+ hr = cmos_bcd_read(RTC_HOURS_ALARM, rtc_control);
/* If we ever get an FACP with proper values... */
- if (acpi_gbl_FADT.day_alarm)
+ if (acpi_gbl_FADT.day_alarm) {
/* ACPI spec: only low 6 its should be cared */
day = CMOS_READ(acpi_gbl_FADT.day_alarm) & 0x3F;
- else
- day = CMOS_READ(RTC_DAY_OF_MONTH);
+ if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
+ day = bcd2bin(day);
+ } else
+ day = cmos_bcd_read(RTC_DAY_OF_MONTH, rtc_control);
if (acpi_gbl_FADT.month_alarm)
- mo = CMOS_READ(acpi_gbl_FADT.month_alarm);
- else
- mo = CMOS_READ(RTC_MONTH);
+ mo = cmos_bcd_read(acpi_gbl_FADT.month_alarm, rtc_control);
+ else {
+ mo = cmos_bcd_read(RTC_MONTH, rtc_control);
+ today = cmos_bcd_read(RTC_DAY_OF_MONTH, rtc_control);
+ }
if (acpi_gbl_FADT.century)
- cent = CMOS_READ(acpi_gbl_FADT.century);
+ cent = cmos_bcd_read(acpi_gbl_FADT.century, rtc_control);
- yr = CMOS_READ(RTC_YEAR);
+ yr = cmos_bcd_read(RTC_YEAR, rtc_control);
spin_unlock_irqrestore(&rtc_lock, flags);
- if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
- sec = bcd2bin(sec);
- min = bcd2bin(min);
- hr = bcd2bin(hr);
- day = bcd2bin(day);
- mo = bcd2bin(mo);
- yr = bcd2bin(yr);
- cent = bcd2bin(cent);
- }
-
/* we're trusting the FADT (see above) */
if (!acpi_gbl_FADT.century)
/* If we're not trusting the FADT, we should at least make it
@@ -153,6 +150,20 @@ static int acpi_system_alarm_seq_show(struct seq_file *seq, void *offset)
else
yr += cent * 100;
+ /*
+ * Show correct dates for alarms up to a month into the future.
+ * This solves issues for nearly all situations with the common
+ * 30-day alarm clocks in PC hardware.
+ */
+ if (day < today) {
+ if (mo < 12) {
+ mo += 1;
+ } else {
+ mo = 1;
+ yr += 1;
+ }
+ }
+
seq_printf(seq, "%4.4u-", yr);
(mo > 12) ? seq_puts(seq, "**-") : seq_printf(seq, "%2.2u-", mo);
(day > 31) ? seq_puts(seq, "** ") : seq_printf(seq, "%2.2u ", day);