[PATCH 1/2] Adding rtctest as client test

[PATCH 1/2] Adding rtctest as client test

[Jason Wang]

This new autotest module implements a simple test for the driver of realtime
clock. It do the testing of interrupt, date reading, alarm and
frequency.

Please refer the Documentation/rtc.txt for details.

Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 client/tests/rtc/src/Makefile  |   19 +++
 client/tests/rtc/src/rtctest.c |  261 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 280 insertions(+), 0 deletions(-)
 create mode 100644 client/tests/rtc/src/Makefile
 create mode 100644 client/tests/rtc/src/rtctest.c

diff --git a/client/tests/rtc/control b/client/tests/rtc/control
new file mode 100644
index 0000000..f0f64c9
--- /dev/null
+++ b/client/tests/rtc/control
@@ -0,0 +1,15 @@
+TIME="SHORT"
+AUTHOR = "Jason Wang <jasowag@redhat.com>"
+DOC = """
+rtc is a simple test of realtime clock driver which was grabbed from 
+Documentation/rtc.txt. It does the functional test of interrupt, alarm and 
+requeseted frequency.
+
+Please refer the kernel documentation for details.
+"""
+NAME = 'rtc'
+TEST_CLASS = 'kernel'
+TEST_CATEGORY = 'Functional'
+TEST_TYPE = 'client'
+
+job.run_test('rtc')
diff --git a/client/tests/rtc/rtc.py b/client/tests/rtc/rtc.py
new file mode 100644
index 0000000..d4a1500
--- /dev/null
+++ b/client/tests/rtc/rtc.py
@@ -0,0 +1,23 @@
+import os
+from autotest_lib.client.bin import test, utils
+from autotest_lib.client.common_lib import error
+
+class rtc(test.test):
+    version = 1
+
+    preserve_srcdir = True
+
+    def setup(self):
+        os.chdir(self.srcdir)
+        utils.system('make')
+
+
+    def initialize(self):
+        self.job.require_gcc()
+
+
+    def run_once(self, def_rtc="/dev/rtc0", maxfreq=64):
+        if not os.path.exists(def_rtc):
+            raise error.TestNAError("%s doest not existed." % def_rtc)
+        result = utils.system(self.srcdir + '/rtctest %s %s' % (def_rtc,
+                                                                maxfreq))
diff --git a/client/tests/rtc/src/Makefile b/client/tests/rtc/src/Makefile
new file mode 100644
index 0000000..f99dc60
--- /dev/null
+++ b/client/tests/rtc/src/Makefile
@@ -0,0 +1,19 @@
+CC=		cc
+CFLAGS=	        -O -Wall -Wstrict-prototypes
+
+PROGS=		rtctest
+
+SRCS=		rtctest.c
+OBJS=		${SRCS:.c=.o}
+
+
+all:		$(PROGS)
+
+rtctest:	$(OBJS)
+		$(CC) $(LDFLAGS) -o rtctest $(OBJS)
+
+clean:
+		-rm -f $(OBJS)
+
+clobber:	clean
+		-rm -f $(PROGS)
diff --git a/client/tests/rtc/src/rtctest.c b/client/tests/rtc/src/rtctest.c
new file mode 100644
index 0000000..25b74af
--- /dev/null
+++ b/client/tests/rtc/src/rtctest.c
@@ -0,0 +1,261 @@
+/*
+ *      Real Time Clock Driver Test/Example Program
+ *
+ *      Compile with:
+ *		     gcc -s -Wall -Wstrict-prototypes rtctest.c -o rtctest
+ *
+ *      Copyright (C) 1996, Paul Gortmaker.
+ *      Copyright (C) 2010, Jason Wang <jasowang@redhat.com>
+ *
+ *      Released under the GNU General Public License, version 2,
+ *      included herein by reference.
+ *
+ */
+
+#include <stdio.h>
+#include <linux/rtc.h>
+#include <sys/ioctl.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <errno.h>
+
+
+/*
+ * This expects the new RTC class driver framework, working with
+ * clocks that will often not be clones of what the PC-AT had.
+ * Use the command line to specify another RTC if you need one.
+ */
+static const char default_rtc[] = "/dev/rtc0";
+static int maxfreq = 64;
+
+int main(int argc, char **argv)
+{
+	int i, fd, retval, irqcount = 0;
+	unsigned long tmp, data;
+	struct rtc_time rtc_tm;
+	const char *rtc = default_rtc;
+
+	switch (argc) {
+	case 3:
+	        maxfreq = atoi(argv[2]);
+	case 2:
+		rtc = argv[1];
+		/* FALLTHROUGH */
+	case 1:
+		break;
+	default:
+		fprintf(stderr, "usage:  rtctest [rtcdev] [maxfreq]\n");
+		return 1;
+	}
+
+	fd = open(rtc, O_RDONLY);
+
+	if (fd ==  -1) {
+		perror(rtc);
+		exit(errno);
+	}
+
+	fprintf(stderr, "\n\t\t\tRTC Driver Test Example.\n\n");
+
+	/* Turn on update interrupts (one per second) */
+	retval = ioctl(fd, RTC_UIE_ON, 0);
+	if (retval == -1) {
+		if (errno == ENOTTY) {
+			fprintf(stderr,
+				"\n...Update IRQs not supported.\n");
+			goto test_READ;
+		}
+		perror("RTC_UIE_ON ioctl");
+		exit(errno);
+	}
+
+	fprintf(stderr, "Counting 5 update (1/sec) interrupts from reading %s:",
+			rtc);
+	fflush(stderr);
+	for (i=1; i<6; i++) {
+		/* This read will block */
+		retval = read(fd, &data, sizeof(unsigned long));
+		if (retval == -1) {
+			perror("read");
+			exit(errno);
+		}
+		fprintf(stderr, " %d",i);
+		fflush(stderr);
+		irqcount++;
+	}
+
+	fprintf(stderr, "\nAgain, from using select(2) on /dev/rtc:");
+	fflush(stderr);
+	for (i=1; i<6; i++) {
+		struct timeval tv = {5, 0};     /* 5 second timeout on select */
+		fd_set readfds;
+
+		FD_ZERO(&readfds);
+		FD_SET(fd, &readfds);
+		/* The select will wait until an RTC interrupt happens. */
+		retval = select(fd+1, &readfds, NULL, NULL, &tv);
+		if (retval == -1) {
+		        perror("select");
+		        exit(errno);
+		}
+		/* This read won't block unlike the select-less case above. */
+		retval = read(fd, &data, sizeof(unsigned long));
+		if (retval == -1) {
+		        perror("read");
+		        exit(errno);
+		}
+		fprintf(stderr, " %d",i);
+		fflush(stderr);
+		irqcount++;
+	}
+
+	/* Turn off update interrupts */
+	retval = ioctl(fd, RTC_UIE_OFF, 0);
+	if (retval == -1) {
+		perror("RTC_UIE_OFF ioctl");
+		exit(errno);
+	}
+
+test_READ:
+	/* Read the RTC time/date */
+	retval = ioctl(fd, RTC_RD_TIME, &rtc_tm);
+	if (retval == -1) {
+		perror("RTC_RD_TIME ioctl");
+		exit(errno);
+	}
+
+	fprintf(stderr, "\n\nCurrent RTC date/time is %d-%d-%d, %02d:%02d:%02d.\n",
+		rtc_tm.tm_mday, rtc_tm.tm_mon + 1, rtc_tm.tm_year + 1900,
+		rtc_tm.tm_hour, rtc_tm.tm_min, rtc_tm.tm_sec);
+
+	/* Set the alarm to 5 sec in the future, and check for rollover */
+	rtc_tm.tm_sec += 5;
+	if (rtc_tm.tm_sec >= 60) {
+		rtc_tm.tm_sec %= 60;
+		rtc_tm.tm_min++;
+	}
+	if (rtc_tm.tm_min == 60) {
+		rtc_tm.tm_min = 0;
+		rtc_tm.tm_hour++;
+	}
+	if (rtc_tm.tm_hour == 24)
+		rtc_tm.tm_hour = 0;
+
+	retval = ioctl(fd, RTC_ALM_SET, &rtc_tm);
+	if (retval == -1) {
+		if (errno == ENOTTY) {
+			fprintf(stderr,
+				"\n...Alarm IRQs not supported.\n");
+			goto test_PIE;
+		}
+		perror("RTC_ALM_SET ioctl");
+		exit(errno);
+	}
+
+	/* Read the current alarm settings */
+	retval = ioctl(fd, RTC_ALM_READ, &rtc_tm);
+	if (retval == -1) {
+		perror("RTC_ALM_READ ioctl");
+		exit(errno);
+	}
+
+	fprintf(stderr, "Alarm time now set to %02d:%02d:%02d.\n",
+		rtc_tm.tm_hour, rtc_tm.tm_min, rtc_tm.tm_sec);
+
+	/* Enable alarm interrupts */
+	retval = ioctl(fd, RTC_AIE_ON, 0);
+	if (retval == -1) {
+		perror("RTC_AIE_ON ioctl");
+		exit(errno);
+	}
+
+	fprintf(stderr, "Waiting 5 seconds for alarm...");
+	fflush(stderr);
+	/* This blocks until the alarm ring causes an interrupt */
+	retval = read(fd, &data, sizeof(unsigned long));
+	if (retval == -1) {
+		perror("read");
+		exit(errno);
+	}
+	irqcount++;
+	fprintf(stderr, " okay. Alarm rang.\n");
+
+	/* Disable alarm interrupts */
+	retval = ioctl(fd, RTC_AIE_OFF, 0);
+	if (retval == -1) {
+		perror("RTC_AIE_OFF ioctl");
+		exit(errno);
+	}
+
+test_PIE:
+	/* Read periodic IRQ rate */
+	retval = ioctl(fd, RTC_IRQP_READ, &tmp);
+	if (retval == -1) {
+		/* not all RTCs support periodic IRQs */
+		if (errno == ENOTTY) {
+			fprintf(stderr, "\nNo periodic IRQ support\n");
+			goto done;
+		}
+		perror("RTC_IRQP_READ ioctl");
+		exit(errno);
+	}
+	fprintf(stderr, "\nPeriodic IRQ rate is %ldHz.\n", tmp);
+
+	fprintf(stderr, "Counting 20 interrupts at:");
+	fflush(stderr);
+
+	/* The frequencies 128Hz, 256Hz, ... 8192Hz are only allowed for root. */
+	for (tmp=2; tmp<=maxfreq; tmp*=2) {
+
+		retval = ioctl(fd, RTC_IRQP_SET, tmp);
+		if (retval == -1) {
+			/* not all RTCs can change their periodic IRQ rate */
+			if (errno == ENOTTY) {
+				fprintf(stderr,
+					"\n...Periodic IRQ rate is fixed\n");
+				goto done;
+			}
+			perror("RTC_IRQP_SET ioctl");
+			exit(errno);
+		}
+
+		fprintf(stderr, "\n%ldHz:\t", tmp);
+		fflush(stderr);
+
+		/* Enable periodic interrupts */
+		retval = ioctl(fd, RTC_PIE_ON, 0);
+		if (retval == -1) {
+			perror("RTC_PIE_ON ioctl");
+			exit(errno);
+		}
+
+		for (i=1; i<21; i++) {
+			/* This blocks */
+			retval = read(fd, &data, sizeof(unsigned long));
+			if (retval == -1) {
+				perror("read");
+				exit(errno);
+			}
+			fprintf(stderr, " %d",i);
+			fflush(stderr);
+			irqcount++;
+		}
+
+		/* Disable periodic interrupts */
+		retval = ioctl(fd, RTC_PIE_OFF, 0);
+		if (retval == -1) {
+			perror("RTC_PIE_OFF ioctl");
+			exit(errno);
+		}
+	}
+
+done:
+	fprintf(stderr, "\n\n\t\t\t *** Test complete ***\n");
+
+	close(fd);
+
+	return 0;
+}

[PATCH 2/2] KVM test: Add rtc into the guest test

[Jason Wang]

rtc test is a test for rtc driver which could also be useful for
testing the rtc emulation in kvm.

Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 0 files changed, 0 insertions(+), 0 deletions(-)

diff --git a/client/tests/kvm/autotest_control/rtc.control b/client/tests/kvm/autotest_control/rtc.control
new file mode 100644
index 0000000..b7597e3
--- /dev/null
+++ b/client/tests/kvm/autotest_control/rtc.control
@@ -0,0 +1,15 @@
+TIME="SHORT"
+AUTHOR = "Jason Wang <jasowag@redhat.com>"
+DOC = """
+rtc is a simple test of realtime clock driver which was grabbed from 
+Documentation/rtc.txt. It does the functional test of interrupt, alarm and 
+requeseted frequency.
+
+Please refer the kernel documentation for details.
+"""
+NAME = 'rtc'
+TEST_CLASS = 'kernel'
+TEST_CATEGORY = 'Functional'
+TEST_TYPE = 'client'
+
+job.run_test('rtc', maxfreq=8192)
diff --git a/client/tests/kvm/tests_base.cfg.sample b/client/tests/kvm/tests_base.cfg.sample
index bb3646c..b003a3e 100644
--- a/client/tests/kvm/tests_base.cfg.sample
+++ b/client/tests/kvm/tests_base.cfg.sample
@@ -151,6 +151,8 @@ variants:
                 test_control_file = scrashme.control
             - hwclock:
                 test_control_file = hwclock.control
+            - rtc:
+                test_control_file = rtc.control
 
     - linux_s3:     install setup unattended_install
         type = linux_s3

Re: [PATCH 1/2] Adding rtctest as client test

[Lucas Meneghel Rodrigues]

On Mon, 2010-05-17 at 15:25 +0800, Jason Wang wrote:
> This new autotest module implements a simple test for the driver of realtime
> clock. It do the testing of interrupt, date reading, alarm and
> frequency.

Ok, patchset applied, thank you!

> Please refer the Documentation/rtc.txt for details.
> 
> Signed-off-by: Jason Wang <jasowang@redhat.com>
> ---
>  client/tests/rtc/src/Makefile  |   19 +++
>  client/tests/rtc/src/rtctest.c |  261 ++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 280 insertions(+), 0 deletions(-)
>  create mode 100644 client/tests/rtc/src/Makefile
>  create mode 100644 client/tests/rtc/src/rtctest.c
> 
> diff --git a/client/tests/rtc/control b/client/tests/rtc/control
> new file mode 100644
> index 0000000..f0f64c9
> --- /dev/null
> +++ b/client/tests/rtc/control
> @@ -0,0 +1,15 @@
> +TIME="SHORT"
> +AUTHOR = "Jason Wang <jasowag@redhat.com>"
> +DOC = """
> +rtc is a simple test of realtime clock driver which was grabbed from 
> +Documentation/rtc.txt. It does the functional test of interrupt, alarm and 
> +requeseted frequency.
> +
> +Please refer the kernel documentation for details.
> +"""
> +NAME = 'rtc'
> +TEST_CLASS = 'kernel'
> +TEST_CATEGORY = 'Functional'
> +TEST_TYPE = 'client'
> +
> +job.run_test('rtc')
> diff --git a/client/tests/rtc/rtc.py b/client/tests/rtc/rtc.py
> new file mode 100644
> index 0000000..d4a1500
> --- /dev/null
> +++ b/client/tests/rtc/rtc.py
> @@ -0,0 +1,23 @@
> +import os
> +from autotest_lib.client.bin import test, utils
> +from autotest_lib.client.common_lib import error
> +
> +class rtc(test.test):
> +    version = 1
> +
> +    preserve_srcdir = True
> +
> +    def setup(self):
> +        os.chdir(self.srcdir)
> +        utils.system('make')
> +
> +
> +    def initialize(self):
> +        self.job.require_gcc()
> +
> +
> +    def run_once(self, def_rtc="/dev/rtc0", maxfreq=64):
> +        if not os.path.exists(def_rtc):
> +            raise error.TestNAError("%s doest not existed." % def_rtc)
> +        result = utils.system(self.srcdir + '/rtctest %s %s' % (def_rtc,
> +                                                                maxfreq))
> diff --git a/client/tests/rtc/src/Makefile b/client/tests/rtc/src/Makefile
> new file mode 100644
> index 0000000..f99dc60
> --- /dev/null
> +++ b/client/tests/rtc/src/Makefile
> @@ -0,0 +1,19 @@
> +CC=		cc
> +CFLAGS=	        -O -Wall -Wstrict-prototypes
> +
> +PROGS=		rtctest
> +
> +SRCS=		rtctest.c
> +OBJS=		${SRCS:.c=.o}
> +
> +
> +all:		$(PROGS)
> +
> +rtctest:	$(OBJS)
> +		$(CC) $(LDFLAGS) -o rtctest $(OBJS)
> +
> +clean:
> +		-rm -f $(OBJS)
> +
> +clobber:	clean
> +		-rm -f $(PROGS)
> diff --git a/client/tests/rtc/src/rtctest.c b/client/tests/rtc/src/rtctest.c
> new file mode 100644
> index 0000000..25b74af
> --- /dev/null
> +++ b/client/tests/rtc/src/rtctest.c
> @@ -0,0 +1,261 @@
> +/*
> + *      Real Time Clock Driver Test/Example Program
> + *
> + *      Compile with:
> + *		     gcc -s -Wall -Wstrict-prototypes rtctest.c -o rtctest
> + *
> + *      Copyright (C) 1996, Paul Gortmaker.
> + *      Copyright (C) 2010, Jason Wang <jasowang@redhat.com>
> + *
> + *      Released under the GNU General Public License, version 2,
> + *      included herein by reference.
> + *
> + */
> +
> +#include <stdio.h>
> +#include <linux/rtc.h>
> +#include <sys/ioctl.h>
> +#include <sys/time.h>
> +#include <sys/types.h>
> +#include <fcntl.h>
> +#include <unistd.h>
> +#include <stdlib.h>
> +#include <errno.h>
> +
> +
> +/*
> + * This expects the new RTC class driver framework, working with
> + * clocks that will often not be clones of what the PC-AT had.
> + * Use the command line to specify another RTC if you need one.
> + */
> +static const char default_rtc[] = "/dev/rtc0";
> +static int maxfreq = 64;
> +
> +int main(int argc, char **argv)
> +{
> +	int i, fd, retval, irqcount = 0;
> +	unsigned long tmp, data;
> +	struct rtc_time rtc_tm;
> +	const char *rtc = default_rtc;
> +
> +	switch (argc) {
> +	case 3:
> +	        maxfreq = atoi(argv[2]);
> +	case 2:
> +		rtc = argv[1];
> +		/* FALLTHROUGH */
> +	case 1:
> +		break;
> +	default:
> +		fprintf(stderr, "usage:  rtctest [rtcdev] [maxfreq]\n");
> +		return 1;
> +	}
> +
> +	fd = open(rtc, O_RDONLY);
> +
> +	if (fd ==  -1) {
> +		perror(rtc);
> +		exit(errno);
> +	}
> +
> +	fprintf(stderr, "\n\t\t\tRTC Driver Test Example.\n\n");
> +
> +	/* Turn on update interrupts (one per second) */
> +	retval = ioctl(fd, RTC_UIE_ON, 0);
> +	if (retval == -1) {
> +		if (errno == ENOTTY) {
> +			fprintf(stderr,
> +				"\n...Update IRQs not supported.\n");
> +			goto test_READ;
> +		}
> +		perror("RTC_UIE_ON ioctl");
> +		exit(errno);
> +	}
> +
> +	fprintf(stderr, "Counting 5 update (1/sec) interrupts from reading %s:",
> +			rtc);
> +	fflush(stderr);
> +	for (i=1; i<6; i++) {
> +		/* This read will block */
> +		retval = read(fd, &data, sizeof(unsigned long));
> +		if (retval == -1) {
> +			perror("read");
> +			exit(errno);
> +		}
> +		fprintf(stderr, " %d",i);
> +		fflush(stderr);
> +		irqcount++;
> +	}
> +
> +	fprintf(stderr, "\nAgain, from using select(2) on /dev/rtc:");
> +	fflush(stderr);
> +	for (i=1; i<6; i++) {
> +		struct timeval tv = {5, 0};     /* 5 second timeout on select */
> +		fd_set readfds;
> +
> +		FD_ZERO(&readfds);
> +		FD_SET(fd, &readfds);
> +		/* The select will wait until an RTC interrupt happens. */
> +		retval = select(fd+1, &readfds, NULL, NULL, &tv);
> +		if (retval == -1) {
> +		        perror("select");
> +		        exit(errno);
> +		}
> +		/* This read won't block unlike the select-less case above. */
> +		retval = read(fd, &data, sizeof(unsigned long));
> +		if (retval == -1) {
> +		        perror("read");
> +		        exit(errno);
> +		}
> +		fprintf(stderr, " %d",i);
> +		fflush(stderr);
> +		irqcount++;
> +	}
> +
> +	/* Turn off update interrupts */
> +	retval = ioctl(fd, RTC_UIE_OFF, 0);
> +	if (retval == -1) {
> +		perror("RTC_UIE_OFF ioctl");
> +		exit(errno);
> +	}
> +
> +test_READ:
> +	/* Read the RTC time/date */
> +	retval = ioctl(fd, RTC_RD_TIME, &rtc_tm);
> +	if (retval == -1) {
> +		perror("RTC_RD_TIME ioctl");
> +		exit(errno);
> +	}
> +
> +	fprintf(stderr, "\n\nCurrent RTC date/time is %d-%d-%d, %02d:%02d:%02d.\n",
> +		rtc_tm.tm_mday, rtc_tm.tm_mon + 1, rtc_tm.tm_year + 1900,
> +		rtc_tm.tm_hour, rtc_tm.tm_min, rtc_tm.tm_sec);
> +
> +	/* Set the alarm to 5 sec in the future, and check for rollover */
> +	rtc_tm.tm_sec += 5;
> +	if (rtc_tm.tm_sec >= 60) {
> +		rtc_tm.tm_sec %= 60;
> +		rtc_tm.tm_min++;
> +	}
> +	if (rtc_tm.tm_min == 60) {
> +		rtc_tm.tm_min = 0;
> +		rtc_tm.tm_hour++;
> +	}
> +	if (rtc_tm.tm_hour == 24)
> +		rtc_tm.tm_hour = 0;
> +
> +	retval = ioctl(fd, RTC_ALM_SET, &rtc_tm);
> +	if (retval == -1) {
> +		if (errno == ENOTTY) {
> +			fprintf(stderr,
> +				"\n...Alarm IRQs not supported.\n");
> +			goto test_PIE;
> +		}
> +		perror("RTC_ALM_SET ioctl");
> +		exit(errno);
> +	}
> +
> +	/* Read the current alarm settings */
> +	retval = ioctl(fd, RTC_ALM_READ, &rtc_tm);
> +	if (retval == -1) {
> +		perror("RTC_ALM_READ ioctl");
> +		exit(errno);
> +	}
> +
> +	fprintf(stderr, "Alarm time now set to %02d:%02d:%02d.\n",
> +		rtc_tm.tm_hour, rtc_tm.tm_min, rtc_tm.tm_sec);
> +
> +	/* Enable alarm interrupts */
> +	retval = ioctl(fd, RTC_AIE_ON, 0);
> +	if (retval == -1) {
> +		perror("RTC_AIE_ON ioctl");
> +		exit(errno);
> +	}
> +
> +	fprintf(stderr, "Waiting 5 seconds for alarm...");
> +	fflush(stderr);
> +	/* This blocks until the alarm ring causes an interrupt */
> +	retval = read(fd, &data, sizeof(unsigned long));
> +	if (retval == -1) {
> +		perror("read");
> +		exit(errno);
> +	}
> +	irqcount++;
> +	fprintf(stderr, " okay. Alarm rang.\n");
> +
> +	/* Disable alarm interrupts */
> +	retval = ioctl(fd, RTC_AIE_OFF, 0);
> +	if (retval == -1) {
> +		perror("RTC_AIE_OFF ioctl");
> +		exit(errno);
> +	}
> +
> +test_PIE:
> +	/* Read periodic IRQ rate */
> +	retval = ioctl(fd, RTC_IRQP_READ, &tmp);
> +	if (retval == -1) {
> +		/* not all RTCs support periodic IRQs */
> +		if (errno == ENOTTY) {
> +			fprintf(stderr, "\nNo periodic IRQ support\n");
> +			goto done;
> +		}
> +		perror("RTC_IRQP_READ ioctl");
> +		exit(errno);
> +	}
> +	fprintf(stderr, "\nPeriodic IRQ rate is %ldHz.\n", tmp);
> +
> +	fprintf(stderr, "Counting 20 interrupts at:");
> +	fflush(stderr);
> +
> +	/* The frequencies 128Hz, 256Hz, ... 8192Hz are only allowed for root. */
> +	for (tmp=2; tmp<=maxfreq; tmp*=2) {
> +
> +		retval = ioctl(fd, RTC_IRQP_SET, tmp);
> +		if (retval == -1) {
> +			/* not all RTCs can change their periodic IRQ rate */
> +			if (errno == ENOTTY) {
> +				fprintf(stderr,
> +					"\n...Periodic IRQ rate is fixed\n");
> +				goto done;
> +			}
> +			perror("RTC_IRQP_SET ioctl");
> +			exit(errno);
> +		}
> +
> +		fprintf(stderr, "\n%ldHz:\t", tmp);
> +		fflush(stderr);
> +
> +		/* Enable periodic interrupts */
> +		retval = ioctl(fd, RTC_PIE_ON, 0);
> +		if (retval == -1) {
> +			perror("RTC_PIE_ON ioctl");
> +			exit(errno);
> +		}
> +
> +		for (i=1; i<21; i++) {
> +			/* This blocks */
> +			retval = read(fd, &data, sizeof(unsigned long));
> +			if (retval == -1) {
> +				perror("read");
> +				exit(errno);
> +			}
> +			fprintf(stderr, " %d",i);
> +			fflush(stderr);
> +			irqcount++;
> +		}
> +
> +		/* Disable periodic interrupts */
> +		retval = ioctl(fd, RTC_PIE_OFF, 0);
> +		if (retval == -1) {
> +			perror("RTC_PIE_OFF ioctl");
> +			exit(errno);
> +		}
> +	}
> +
> +done:
> +	fprintf(stderr, "\n\n\t\t\t *** Test complete ***\n");
> +
> +	close(fd);
> +
> +	return 0;
> +}
>