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authorMatt Mackall <mpm@selenic.com>2006-03-28 01:56:02 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2006-03-28 09:16:00 -0800
commit59937bcdb2bd759d15c792d9798a00da03bf1f48 (patch)
treebecb72ca7fbbb07e4bd86097f6eb2f529fb3ef8e /arch/ppc/platforms
parent3dedf53bb16e27743e5d1f49dbfecf3e5897befa (diff)
downloadlinux-linaro-stable-59937bcdb2bd759d15c792d9798a00da03bf1f48.tar.gz
[PATCH] RTC: Remove RTC UIP synchronization on PPC CHRP (arch/ppc)
Signed-off-by: Matt Mackall <mpm@selenic.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/ppc/platforms')
-rw-r--r--arch/ppc/platforms/chrp_time.c22
1 files changed, 2 insertions, 20 deletions
diff --git a/arch/ppc/platforms/chrp_time.c b/arch/ppc/platforms/chrp_time.c
index c8627770af13..e103a36e11a5 100644
--- a/arch/ppc/platforms/chrp_time.c
+++ b/arch/ppc/platforms/chrp_time.c
@@ -119,33 +119,15 @@ int chrp_set_rtc_time(unsigned long nowtime)
unsigned long chrp_get_rtc_time(void)
{
unsigned int year, mon, day, hour, min, sec;
- int uip, i;
- /* The Linux interpretation of the CMOS clock register contents:
- * When the Update-In-Progress (UIP) flag goes from 1 to 0, the
- * RTC registers show the second which has precisely just started.
- * Let's hope other operating systems interpret the RTC the same way.
- */
-
- /* Since the UIP flag is set for about 2.2 ms and the clock
- * is typically written with a precision of 1 jiffy, trying
- * to obtain a precision better than a few milliseconds is
- * an illusion. Only consistency is interesting, this also
- * allows to use the routine for /dev/rtc without a potential
- * 1 second kernel busy loop triggered by any reader of /dev/rtc.
- */
-
- for ( i = 0; i<1000000; i++) {
- uip = chrp_cmos_clock_read(RTC_FREQ_SELECT);
+ do {
sec = chrp_cmos_clock_read(RTC_SECONDS);
min = chrp_cmos_clock_read(RTC_MINUTES);
hour = chrp_cmos_clock_read(RTC_HOURS);
day = chrp_cmos_clock_read(RTC_DAY_OF_MONTH);
mon = chrp_cmos_clock_read(RTC_MONTH);
year = chrp_cmos_clock_read(RTC_YEAR);
- uip |= chrp_cmos_clock_read(RTC_FREQ_SELECT);
- if ((uip & RTC_UIP)==0) break;
- }
+ } while (sec != chrp_cmos_clock_read(RTC_SECONDS));
if (!(chrp_cmos_clock_read(RTC_CONTROL) & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
{