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
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| @@ -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); | |