5 # Test is executed by writing and reading to /sys/kernel/debug/udelay_test
6 # and exercises a variety of delays to ensure that udelay() is delaying
7 # at least as long as requested (as compared to ktime).
9 # Copyright (C) 2014 Google, Inc.
11 # This software is licensed under the terms of the GNU General Public
12 # License version 2, as published by the Free Software Foundation, and
13 # may be copied, distributed, and modified under those terms.
15 # This program is distributed in the hope that it will be useful,
16 # but WITHOUT ANY WARRANTY; without even the implied warranty of
17 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 # GNU General Public License for more details.
20 MODULE_NAME=udelay_test
21 UDELAY_PATH=/sys/kernel/debug/udelay_test
25 /sbin/modprobe -q $MODULE_NAME
32 echo $delay > $UDELAY_PATH
33 tee -a $tmp_file < $UDELAY_PATH
38 if [ -f $tmp_file ]; then
41 /sbin/modprobe -q -r $MODULE_NAME
47 # Delay for a variety of times.
48 # 1..200, 200..500 (by 10), 500..2000 (by 100)
49 for (( delay = 1; delay < 200; delay += 1 )); do
52 for (( delay = 200; delay < 500; delay += 10 )); do
55 for (( delay = 500; delay <= 2000; delay += 100 )); do
60 count=`grep -c FAIL $tmp_file`
61 if [ $? -eq "0" ]; then
62 echo "ERROR: $count delays failed to delay long enough"