fix math in acpi_system_write_alarm() (resend)

PATCH In review Jordan Crouse 2 participants 2 messages Sep 26, 2008 – Sep 27, 2008 ACPI

Share & tools

Jordan Crouse

author

2008-09-26 23:29 UTC #0 lore raw

PATCH 1/1 fix math in acpi_system_write_alarm() (resend)

This patch fixes the day of month math in acpi_system_write_alarm(). The previous code assumed that there were 31 days in every month. We caught this on June 30 when the month changed, but the system stayed suspended waiting for June 31st.

I know /proc/acpi/alarm is being deprecated, but its still there, and I think as long as somebody can use it in anger, it should correct.

Thanks,
Jordan

Signature · 3 lines

Jordan Crouse
Systems Software Development Engineer 
Advanced Micro Devices, Inc.

[PATCH] ACPI: Make sure that the alarm math is correct

From: Jordan Crouse <[email protected]>

The current /proc/acpi/alarm math assumes that every month has 31 days. This patch figures out the correct number of days in the month.

Signed-off-by Jordan Crouse <[email protected]>

---

 drivers/acpi/sleep/proc.c |   27 ++++++++++++++++++++++++---
 1 files changed, 24 insertions(+), 3 deletions(-)

drivers/acpi/sleep/proc.c +24 -3

index 4ebbba2..0e75d79 100644
@@ -283,10 +283,31 @@ acpi_system_write_alarm(struct file *file,
 		day += hr/24;
 		hr = hr%24;
 	}
-	if (day > 31) {
-		mo += day/32;
-		day = day%32;
+
+	while (1) {
+		int tmo  = mo % 13;
+		int dinmo;
+
+		if (tmo == 2) {
+			if (((yr % 4 == 0) && (yr % 100 != 0)) ||
+			    (yr % 400 == 0))
+				dinmo = 29;
+			else
+				dinmo = 28;
+		} else if (tmo == 1 || tmo == 3 || tmo == 5 ||
+			   tmo == 7 || tmo == 8 || tmo == 10 ||
+			   tmo == 12)
+			 dinmo = 31;
+		else
+			dinmo = 30;
+
+		if (day <= dinmo)
+			break;
+
+		mo  += 1;
+		day -= dinmo;
 	}
+
 	if (mo > 12) {
 		yr += mo/13;
 		mo = mo%13;

Zhang Rui

2008-09-27 02:11 UTC #1 lore raw

Quoted 9 lines · Jordan Crouse

This patch fixes the day of month math in acpi_system_write_alarm(). The previous code assumed that there were 31 days in every month. We caught this on June 30 when the month changed, but the system stayed suspended waiting for June 31st.
I know /proc/acpi/alarm is being deprecated, but its still there, and I think as long as somebody can use it in anger, it should correct.

agree.

len, I think we should also apply this patch.

Subject: ACPI: deprecate /proc/acpi/alarm

/proc/acpi/alarm is deprecated.
users can use /sys/class/rtc/rtcX/wakealarm instead.

Signed-off-by Zhang Rui <[email protected]>

---
 drivers/acpi/Kconfig      |    1 +
 drivers/acpi/sleep/proc.c |    2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

drivers/acpi/sleep/proc.c +1 -1

Index: linux-2.6/drivers/acpi/sleep/proc.c
===================================================================
@@ -78,7 +78,7 @@ acpi_system_write_sleep(struct file *fil
 }
 #endif				/* CONFIG_ACPI_PROCFS */
 
-#if defined(CONFIG_RTC_DRV_CMOS) || defined(CONFIG_RTC_DRV_CMOS_MODULE) || !defined(CONFIG_X86)
+#if defined(CONFIG_RTC_DRV_CMOS) || defined(CONFIG_RTC_DRV_CMOS_MODULE) || !defined(CONFIG_X86) || !define(CONFIG_ACPI_PROCFS)
 /* use /sys/class/rtc/rtcX/wakealarm instead; it's not ACPI-specific */
 #else
 #define	HAVE_ACPI_LEGACY_ALARM

drivers/acpi/Kconfig +1 -0

Index: linux-2.6/drivers/acpi/Kconfig
===================================================================
@@ -60,6 +60,7 @@ config ACPI_PROCFS
 	  /proc/acpi/fadt (/sys/firmware/acpi/tables/FACP)
 	  /proc/acpi/debug_layer (/sys/module/acpi/parameters/debug_layer)
 	  /proc/acpi/debug_level (/sys/module/acpi/parameters/debug_level)
+	  /proc/acpi/alarm (/sys/class/rtc/rtcX/wakealarm)
 
 	  This option has no effect on /proc/acpi/ files
 	  and functions which do not yet exist in /sys.