[TRIVIAL] 2.5.59 RTC alarm and wildcards

Rusty Trivial Russell (rusty@rustcorp.com.au)
Thu, 06 Feb 2003 16:51:44 +1100


(Included in 2.4)
From: Paul Gortmaker <p_gortmaker@yahoo.com>

NB: patch for 2.4 and 2.2 already sent to Marcelo and Alan.

Paul.

----------

Summary: Wildcards in RTC alarm settings failed to work

Description:
The RTC has provision for wildcards when setting the alarm; to
use them you have to write a value higher than 0xc0 to the
appropriate hr/min/sec entry. The driver used 0xff, which is
fine, but it mistakenly fed the 0xff through BIN_TO_BCD before
writing them (which is < 0xc0) and so wildcards didn't work.
(Thanks to Gerhard Kurz for reporting the bug.)


--- trivial-2.5-bk/drivers/char/rtc.c.orig 2003-02-06 16:30:20.000000000 +1100
+++ trivial-2.5-bk/drivers/char/rtc.c 2003-02-06 16:30:20.000000000 +1100
@@ -171,7 +171,7 @@
* A very tiny interrupt handler. It runs with SA_INTERRUPT set,
* but there is possibility of conflicting with the set_rtc_mmss()
* call (the rtc irq and the timer irq can easily run at the same
- * time in two different CPUs). So we need to serializes
+ * time in two different CPUs). So we need to serialize
* accesses to the chip with the rtc_lock spinlock that each
* architecture should implement in the timer code.
* (See ./arch/XXXX/kernel/time.c for the set_rtc_mmss() function.)
@@ -401,22 +401,18 @@
min = alm_tm.tm_min;
sec = alm_tm.tm_sec;

- if (hrs >= 24)
- hrs = 0xff;
-
- if (min >= 60)
- min = 0xff;
-
- if (sec >= 60)
- sec = 0xff;
-
spin_lock_irq(&rtc_lock);
if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) ||
RTC_ALWAYS_BCD)
{
- BIN_TO_BCD(sec);
- BIN_TO_BCD(min);
- BIN_TO_BCD(hrs);
+ if (sec < 60) BIN_TO_BCD(sec);
+ else sec = 0xff;
+
+ if (min < 60) BIN_TO_BCD(min);
+ else min = 0xff;
+
+ if (hrs < 24) BIN_TO_BCD(hrs);
+ else hrs = 0xff;
}
CMOS_WRITE(hrs, RTC_HOURS_ALARM);
CMOS_WRITE(min, RTC_MINUTES_ALARM);

-- 
  Don't blame me: the Monkey is driving
  File: Paul Gortmaker <p_gortmaker@yahoo.com>: [PATCH] 2.5.59 RTC alarm and wildcards
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/