From 0b63accf87225b5eb7e52814c374cf02d733d4bb Mon Sep 17 00:00:00 2001 From: Prarit Bhargava Date: Wed, 18 Mar 2015 15:46:33 -0400 Subject: 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 Acked-by: John Stultz 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 --- tools/testing/selftests/timers/rtctest.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'tools/testing/selftests/timers') 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++; -- cgit v1.2.3-59-g8ed1b