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authorPrarit Bhargava <prarit@redhat.com>2015-03-18 20:46:33 +0100
committerShuah Khan <shuahkh@osg.samsung.com>2015-03-25 05:02:59 +0100
commit0b63accf87225b5eb7e52814c374cf02d733d4bb (patch)
tree910f533f4eb0323ae0f9b0ee09109306c3eeeea9 /tools/testing
parentDocumentation, split up rtc.txt into documentation and test file (diff)
downloadlinux-0b63accf87225b5eb7e52814c374cf02d733d4bb.tar.xz
linux-0b63accf87225b5eb7e52814c374cf02d733d4bb.zip
tools, update rtctest.c to verify passage of time
rtctest.c checks to see if PIE is functioning by testing if 20 interrupts occur at rates from 2HZ to 64HZ. While this check is good, it does not check to see if the correct amount of time has actually passed. This misses situations where the RTC may be operating at a higher or lower frequency than expected. This patch introduces a simple check to verify if the time passed is less than 10% of what was programmed into the RTC. Signed-off-by: Prarit Bhargava <prarit@redhat.com> Acked-by: John Stultz <john.stultz@linaro.org> Cc: corbet@lwn.net Cc: rtc-linux@googlegroups.com Cc: linux-doc@vger.kernel.org Cc: a.zummo@towertech.it Cc: prarit@redhat.com Cc: john.stultz@linaro.org Cc: shuahkh@osg.samsung.com Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Diffstat (limited to 'tools/testing')
-rw-r--r--tools/testing/selftests/timers/rtctest.c13
1 files changed, 13 insertions, 0 deletions
diff --git a/tools/testing/selftests/timers/rtctest.c b/tools/testing/selftests/timers/rtctest.c
index 1e06f4602195..d80ae852334d 100644
--- a/tools/testing/selftests/timers/rtctest.c
+++ b/tools/testing/selftests/timers/rtctest.c
@@ -36,6 +36,7 @@ int main(int argc, char **argv)
unsigned long tmp, data;
struct rtc_time rtc_tm;
const char *rtc = default_rtc;
+ struct timeval start, end, diff;
switch (argc) {
case 2:
@@ -230,12 +231,24 @@ test_PIE:
}
for (i=1; i<21; i++) {
+ gettimeofday(&start, NULL);
/* This blocks */
retval = read(fd, &data, sizeof(unsigned long));
if (retval == -1) {
perror("read");
exit(errno);
}
+ gettimeofday(&end, NULL);
+ timersub(&end, &start, &diff);
+ if (diff.tv_sec > 0 ||
+ diff.tv_usec > ((1000000L / tmp) * 1.10)) {
+ fprintf(stderr, "\nPIE delta error: %ld.%06ld should be close to 0.%06ld\n",
+ diff.tv_sec, diff.tv_usec,
+ (1000000L / tmp));
+ fflush(stdout);
+ exit(-1);
+ }
+
fprintf(stderr, " %d",i);
fflush(stderr);
irqcount++;