mirror of
https://github.com/torvalds/linux.git
synced 2024-11-24 05:02:12 +00:00
Merge branch 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: rtc: fix deadlock
This commit is contained in:
commit
426e1eafdb
@ -15,6 +15,7 @@
|
||||
#include <linux/mc146818rtc.h>
|
||||
#include <linux/rtc.h>
|
||||
#include <linux/bcd.h>
|
||||
#include <linux/delay.h>
|
||||
|
||||
#define RTC_PIE 0x40 /* periodic interrupt enable */
|
||||
#define RTC_AIE 0x20 /* alarm interrupt enable */
|
||||
@ -43,7 +44,6 @@ static inline unsigned char rtc_is_updating(void)
|
||||
|
||||
static inline unsigned int get_rtc_time(struct rtc_time *time)
|
||||
{
|
||||
unsigned long uip_watchdog = jiffies;
|
||||
unsigned char ctrl;
|
||||
unsigned long flags;
|
||||
|
||||
@ -53,19 +53,15 @@ static inline unsigned int get_rtc_time(struct rtc_time *time)
|
||||
|
||||
/*
|
||||
* read RTC once any update in progress is done. The update
|
||||
* can take just over 2ms. We wait 10 to 20ms. There is no need to
|
||||
* can take just over 2ms. We wait 20ms. There is no need to
|
||||
* to poll-wait (up to 1s - eeccch) for the falling edge of RTC_UIP.
|
||||
* If you need to know *exactly* when a second has started, enable
|
||||
* periodic update complete interrupts, (via ioctl) and then
|
||||
* immediately read /dev/rtc which will block until you get the IRQ.
|
||||
* Once the read clears, read the RTC time (again via ioctl). Easy.
|
||||
*/
|
||||
|
||||
if (rtc_is_updating() != 0)
|
||||
while (jiffies - uip_watchdog < 2*HZ/100) {
|
||||
barrier();
|
||||
cpu_relax();
|
||||
}
|
||||
if (rtc_is_updating())
|
||||
mdelay(20);
|
||||
|
||||
/*
|
||||
* Only the values that we read from the RTC are set. We leave
|
||||
|
Loading…
Reference in New Issue
Block a user