提交 4af6ec46 编写于 作者: M Matt Mackall 提交者: Linus Torvalds

[PATCH] RTC: Remove RTC UIP synchronization on ARM

Signed-off-by: NMatt Mackall <mpm@selenic.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
上级 6f0d7bd6
......@@ -34,27 +34,12 @@ static int rtc_base;
static unsigned long __init get_isa_cmos_time(void)
{
unsigned int year, mon, day, hour, min, sec;
int i;
// check to see if the RTC makes sense.....
if ((CMOS_READ(RTC_VALID) & RTC_VRT) == 0)
return mktime(1970, 1, 1, 0, 0, 0);
/* 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.
*/
/* read RTC exactly on falling edge of update flag */
for (i = 0 ; i < 1000000 ; i++) /* may take up to 1 second... */
if (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP)
break;
for (i = 0 ; i < 1000000 ; i++) /* must try at least 2.228 ms */
if (!(CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP))
break;
do { /* Isn't this overkill ? UIP above should guarantee consistency */
do {
sec = CMOS_READ(RTC_SECONDS);
min = CMOS_READ(RTC_MINUTES);
hour = CMOS_READ(RTC_HOURS);
......
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