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authorMark Brown <broonie@kernel.org>2017-04-25 16:35:35 +0100
committerMark Brown <broonie@kernel.org>2017-04-25 16:35:35 +0100
commit9095bf25ea08135a5b74875dd0e3eeaddc4218a0 (patch)
treea4e6976eab0e7a5b6258281077cd5853c7e69514 /include/linux/delay.h
parentcdf4275e957c6bad3756e98942341667f1d7de7d (diff)
parentc1ae3cfa0e89fa1a7ecc4c99031f5e9ae99d9201 (diff)
Merge tag 'v4.11-rc1' into regulator-arizona
Linux 4.11-rc1
Diffstat (limited to 'include/linux/delay.h')
-rw-r--r--include/linux/delay.h11
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>