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| author |   Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2017-05-02 09:48:26 -0700 |
|---|---|---|
| committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2017-05-02 09:48:26 -0700 |
| commit | 0337966d121ebebf73a1c346123e8112796e684e (patch) | |
| tree | c0d4388591e72dc5a26ee976a9cbca70f6bafbbd /include/linux/delay.h | |
| parent | Input: i8042 - add Clevo P650RS to the i8042 reset list (diff) | |
| parent | Input: ar1021_i2c - use BIT to check for a bit (diff) | |
| download | linux-dev-0337966d121ebebf73a1c346123e8112796e684e.tar.xz linux-dev-0337966d121ebebf73a1c346123e8112796e684e.zip | |
Merge branch 'next' into for-linus
Prepare input updates for 4.12 merge window.
Diffstat (limited to 'include/linux/delay.h')
| -rw-r--r-- | include/linux/delay.h | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/include/linux/delay.h b/include/linux/delay.h index a6ecb34cf547..2ecb3c46b20a 100644 --- a/include/linux/delay.h +++ b/include/linux/delay.h @@ -5,6 +5,17 @@ * Copyright (C) 1993 Linus Torvalds * * Delay routines, using a pre-computed "loops_per_jiffy" value. + * + * Please note that ndelay(), udelay() and mdelay() may return early for + * several reasons: + * 1. computed loops_per_jiffy too low (due to the time taken to + * execute the timer interrupt.) + * 2. cache behaviour affecting the time it takes to execute the + * loop function. + * 3. CPU clock rate changes. + * + * Please see this thread: + * http://lists.openwall.net/linux-kernel/2011/01/09/56 */ #include <linux/kernel.h> |