mirror of
https://github.com/FEX-Emu/linux.git
synced 2024-12-16 22:10:24 +00:00
[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>
This commit is contained in:
parent
3dedf53bb1
commit
59937bcdb2
@ -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)
|
||||
{
|
||||
|
Loading…
Reference in New Issue
Block a user