usleep[_range] are finer precision implementations of msleep and are designed to be drop-in replacements for udelay where a precise sleep / busy-wait is unnecessary. They also allow an easy interface to specify slack when a precise (ish) wakeup is unnecessary to help minimize wakeups
Unified · Split
| @@ -45,6 +45,12 @@ extern unsigned long lpj_fine; · 44 unmodified lines | ||
| 45 | 45 | void calibrate_delay(void); |
| 46 | 46 | void msleep(unsigned int msecs); |
| 47 | 47 | unsigned long msleep_interruptible(unsigned int msecs); |
| 48 | +void usleep_range(unsigned long min, unsigned long max); | |
| 49 | + | |
| 50 | +static inline void usleep(unsigned long usecs) | |
| 51 | +{ | |
| 52 | + usleep_range(usecs, usecs); | |
| 53 | +} | |
| 48 | 54 | |
| 49 | 55 | static inline void ssleep(unsigned int seconds) |
| 50 | 56 | { |
| @@ -1755,3 +1755,25 @@ unsigned long msleep_interruptible(unsigned int msecs) · 1754 unmodified lines | ||
| 1755 | 1755 | } |
| 1756 | 1756 | |
| 1757 | 1757 | EXPORT_SYMBOL(msleep_interruptible); |
| 1758 | + | |
| 1759 | +static int __sched do_usleep_range(unsigned long min, unsigned long max) | |
| 1760 | +{ | |
| 1761 | + ktime_t kmin; | |
| 1762 | + unsigned long delta; | |
| 1763 | + | |
| 1764 | + kmin = ktime_set(0, min * NSEC_PER_USEC); | |
| 1765 | + delta = max - min; | |
| 1766 | + return schedule_hrtimeout_range(&kmin, delta, HRTIMER_MODE_REL); | |
| 1767 | +} | |
| 1768 | + | |
| 1769 | +/** | |
| 1770 | + * usleep_range - Drop in replacement for udelay where wakeup is flexible | |
| 1771 | + * @min: Minimum time in usecs to sleep | |
| 1772 | + * @max: Maximum time in usecs to sleep | |
| 1773 | + */ | |
| 1774 | +void usleep_range(unsigned long min, unsigned long max) | |
| 1775 | +{ | |
| 1776 | + __set_current_state(TASK_UNINTERRUPTIBLE); | |
| 1777 | + do_usleep_range(min, max); | |
| 1778 | +} | |
| 1779 | +EXPORT_SYMBOL(usleep_range); | |