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