tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1// SPDX-License-Identifier: MIT
2/* Copyright © 2025 Intel Corporation */
3
4#include <linux/jiffies.h>
5
6#include "i915_timer_util.h"
7
8void cancel_timer(struct timer_list *t)
9{
10 if (!timer_active(t))
11 return;
12
13 timer_delete(t);
14 WRITE_ONCE(t->expires, 0);
15}
16
17void set_timer_ms(struct timer_list *t, unsigned long timeout)
18{
19 if (!timeout) {
20 cancel_timer(t);
21 return;
22 }
23
24 timeout = msecs_to_jiffies(timeout);
25
26 /*
27 * Paranoia to make sure the compiler computes the timeout before
28 * loading 'jiffies' as jiffies is volatile and may be updated in
29 * the background by a timer tick. All to reduce the complexity
30 * of the addition and reduce the risk of losing a jiffy.
31 */
32 barrier();
33
34 /* Keep t->expires = 0 reserved to indicate a canceled timer. */
35 mod_timer(t, jiffies + timeout ?: 1);
36}