diff options
| author | Matt Mackall <mpm@selenic.com> | 2006-03-28 01:56:02 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-03-28 09:16:00 -0800 |
| commit | 59937bcdb2bd759d15c792d9798a00da03bf1f48 (patch) | |
| tree | becb72ca7fbbb07e4bd86097f6eb2f529fb3ef8e /arch/ppc | |
| parent | 3dedf53bb16e27743e5d1f49dbfecf3e5897befa (diff) | |
| download | linux-59937bcdb2bd759d15c792d9798a00da03bf1f48.tar.bz2 | |
[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')
| -rw-r--r-- | arch/ppc/platforms/chrp_time.c | 22 |
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) { |