linux-kernel - [PATCH linux-acpi] Remove superfluous code and correct counting error in function acpi_system_write

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Date:	Thu, 27 Dec 2007 16:41:39 +0800
From:	Yi Yang <yi.y.yang@...el.com>
To:	linux-acpi@...r.kernel.org
Cc:	linux-kernel@...r.kernel.org, lenb@...nel.org,
	acpi-bugzilla@...ts.sourceforge.net
Subject: [PATCH linux-acpi] Remove superfluous code and correct counting
	error in function acpi_system_write_alarm

In function acpi_system_write_alarm in file drivers/acpi/sleep/proc.c,
big sec, min, hr, mo, day and yr are counted twice to get reasonable
values, that is very superfluous, we can do that only once.

In additon, /proc/acpi/alarm can set a related value which can be
specified as YYYY years MM months DD days HH hours MM minutes SS
senconds, it isn't a date, so you can specify as +0000-00-00 96:00:00
, that means 3 days later, current code can't handle such a case.

This patch removes unnecessary code and does with the aforementioned
situation.

Before applying this patch:

[root@...alhost /]# cat /proc/acpi/alarm
2007-12-00 00:00:00
[root@...alhost /]# echo "0000-00-00 96:180:180" > /proc/acpi/alarm
[root@...alhost /]# cat /proc/acpi/alarm
0007-12-02 **:**:**
[root@...alhost /]#

After applying this patch:

[root@...alhost ~]# echo "2007-12-00 00:00:00" > /proc/acpi/alarm
[root@...alhost ~]# cat /proc/acpi/alarm
2007-12-00 00:00:00
[root@...alhost ~]# echo "0000-00-00 96:180:180" > /proc/acpi/alarm
[root@...alhost ~]# cat /proc/acpi/alarm
0007-12-04 03:03:00
[root@...alhost ~]#

Signed-off by Yi Yang <yi.y.yang@...el.com>

diff --git a/drivers/acpi/sleep/proc.c b/drivers/acpi/sleep/proc.c
index fce78fb..f8df521 100644
--- a/drivers/acpi/sleep/proc.c
+++ b/drivers/acpi/sleep/proc.c
@@ -256,27 +256,6 @@ acpi_system_write_alarm(struct file *file,
 	if ((result = get_date_field(&p, &sec)))
 		goto end;
 
-	if (sec > 59) {
-		min += 1;
-		sec -= 60;
-	}
-	if (min > 59) {
-		hr += 1;
-		min -= 60;
-	}
-	if (hr > 23) {
-		day += 1;
-		hr -= 24;
-	}
-	if (day > 31) {
-		mo += 1;
-		day -= 31;
-	}
-	if (mo > 12) {
-		yr += 1;
-		mo -= 12;
-	}
-
 	spin_lock_irq(&rtc_lock);
 
 	rtc_control = CMOS_READ(RTC_CONTROL);
@@ -293,24 +272,24 @@ acpi_system_write_alarm(struct file *file,
 	spin_unlock_irq(&rtc_lock);
 
 	if (sec > 59) {
-		min++;
-		sec -= 60;
+		min += sec/60;
+		sec = sec%60;
 	}
 	if (min > 59) {
-		hr++;
-		min -= 60;
+		hr += min/60;
+		min = min%60;
 	}
 	if (hr > 23) {
-		day++;
-		hr -= 24;
+		day += hr/24;
+		hr = hr%24;
 	}
 	if (day > 31) {
-		mo++;
-		day -= 31;
+		mo += day/32;
+		day = day%32;
 	}
 	if (mo > 12) {
-		yr++;
-		mo -= 12;
+		yr += mo/13;
+		mo = mo%13;
 	}
 
 	spin_lock_irq(&rtc_lock);


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