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authorDavid Riley <davidriley@chromium.org>2014-06-17 01:58:33 +0400
committerJohn Stultz <john.stultz@linaro.org>2014-07-23 21:16:38 +0400
commit988b0c541ed8b1c633c4d4df7169010635942e18 (patch)
treea956d0b955d440e269a20e6fb6d7e888a9128da8
parente704f93af5a083c07b8f722672d63a1d908daf55 (diff)
downloadlinux-988b0c541ed8b1c633c4d4df7169010635942e18.tar.xz
tools: add script to test udelay
This script makes use of the udelay_test module to exercise udelay() and ensure that it is delaying long enough (as compared to ktime). Signed-off-by: David Riley <davidriley@chromium.org> Signed-off-by: John Stultz <john.stultz@linaro.org>
-rwxr-xr-xtools/time/udelay_test.sh66
1 files changed, 66 insertions, 0 deletions
diff --git a/tools/time/udelay_test.sh b/tools/time/udelay_test.sh
new file mode 100755
index 000000000000..12d46b926917
--- /dev/null
+++ b/tools/time/udelay_test.sh
@@ -0,0 +1,66 @@
+#!/bin/bash
+
+# udelay() test script
+#
+# Test is executed by writing and reading to /sys/kernel/debug/udelay_test
+# and exercises a variety of delays to ensure that udelay() is delaying
+# at least as long as requested (as compared to ktime).
+#
+# Copyright (C) 2014 Google, Inc.
+#
+# This software is licensed under the terms of the GNU General Public
+# License version 2, as published by the Free Software Foundation, and
+# may be copied, distributed, and modified under those terms.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+
+MODULE_NAME=udelay_test
+UDELAY_PATH=/sys/kernel/debug/udelay_test
+
+setup()
+{
+ /sbin/modprobe -q $MODULE_NAME
+ tmp_file=`mktemp`
+}
+
+test_one()
+{
+ delay=$1
+ echo $delay > $UDELAY_PATH
+ tee -a $tmp_file < $UDELAY_PATH
+}
+
+cleanup()
+{
+ if [ -f $tmp_file ]; then
+ rm $tmp_file
+ fi
+ /sbin/modprobe -q -r $MODULE_NAME
+}
+
+trap cleanup EXIT
+setup
+
+# Delay for a variety of times.
+# 1..200, 200..500 (by 10), 500..2000 (by 100)
+for (( delay = 1; delay < 200; delay += 1 )); do
+ test_one $delay
+done
+for (( delay = 200; delay < 500; delay += 10 )); do
+ test_one $delay
+done
+for (( delay = 500; delay <= 2000; delay += 100 )); do
+ test_one $delay
+done
+
+# Search for failures
+count=`grep -c FAIL $tmp_file`
+if [ $? -eq "0" ]; then
+ echo "ERROR: $count delays failed to delay long enough"
+ retcode=1
+fi
+
+exit $retcode