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/* SPDX-License-Identifier: MIT */
/* Copyright © 2025 Intel Corporation */
#ifndef __INTEL_DISPLAY_JIFFIES_H__
#define __INTEL_DISPLAY_JIFFIES_H__
#include <linux/jiffies.h>
static inline unsigned long msecs_to_jiffies_timeout(const unsigned int m)
{
unsigned long j = msecs_to_jiffies(m);
return min_t(unsigned long, MAX_JIFFY_OFFSET, j + 1);
}
/*
* If you need to wait X milliseconds between events A and B, but event B
* doesn't happen exactly after event A, you record the timestamp (jiffies) of
* when event A happened, then just before event B you call this function and
* pass the timestamp as the first argument, and X as the second argument.
*/
static inline void
wait_remaining_ms_from_jiffies(unsigned long timestamp_jiffies, int to_wait_ms)
{
unsigned long target_jiffies, tmp_jiffies, remaining_jiffies;
/*
* Don't re-read the value of "jiffies" every time since it may change
* behind our back and break the math.
*/
tmp_jiffies = jiffies;
target_jiffies = timestamp_jiffies +
msecs_to_jiffies_timeout(to_wait_ms);
if (time_after(target_jiffies, tmp_jiffies)) {
remaining_jiffies = target_jiffies - tmp_jiffies;
while (remaining_jiffies)
remaining_jiffies =
schedule_timeout_uninterruptible(remaining_jiffies);
}
}
#endif /* __INTEL_DISPLAY_JIFFIES_H__ */
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