1#!/bin/bash
2# SPDX-License-Identifier: GPL-2.0-only
3
4# udelay() test script
5#
6# Test is executed by writing and reading to /sys/kernel/debug/udelay_test
7# and exercises a variety of delays to ensure that udelay() is delaying
8# at least as long as requested (as compared to ktime).
9#
10# Copyright (C) 2014 Google, Inc.
11#
12
13MODULE_NAME=udelay_test
14UDELAY_PATH=/sys/kernel/debug/udelay_test
15
16setup()
17{
18	/sbin/modprobe -q $MODULE_NAME
19	tmp_file=`mktemp`
20}
21
22test_one()
23{
24	delay=$1
25	echo $delay > $UDELAY_PATH
26	tee -a $tmp_file < $UDELAY_PATH
27}
28
29cleanup()
30{
31	if [ -f $tmp_file ]; then
32		rm $tmp_file
33	fi
34	/sbin/modprobe -q -r $MODULE_NAME
35}
36
37trap cleanup EXIT
38setup
39
40# Delay for a variety of times.
41# 1..200, 200..500 (by 10), 500..2000 (by 100)
42for (( delay = 1; delay < 200; delay += 1 )); do
43	test_one $delay
44done
45for (( delay = 200; delay < 500; delay += 10 )); do
46	test_one $delay
47done
48for (( delay = 500; delay <= 2000; delay += 100 )); do
49	test_one $delay
50done
51
52# Search for failures
53count=`grep -c FAIL $tmp_file`
54if [ $? -eq "0" ]; then
55	echo "ERROR: $count delays failed to delay long enough"
56	retcode=1
57fi
58
59exit $retcode
60