waking system up using RTC (was Re: rtcwakeup.c)

waking system up using RTC (was Re: rtcwakeup.c)

[Pavel Machek]

Hi!

> > p.s. A followup message will include a userspace program which
> >      makes it easier to try the RTC wakeup mechanism.
> 
> For example, if your system actually supports RTC wakeup correctly:
> 
>         rtcwake -t $(date -u -d 'tomorrow 6:30am' +'%s') -m mem
> 
> will set up the system to wake up tomorrow at 6:30am, then suspend-to-RAM by
> writing "mem" to /sys/power/state.  
> 
> Or for testing kernels, unattended scripts like this may help:
> 
>         while true
>         do
>                 echo "suspend-to-disk for 10 minutes starting $(date)"
>                 rtcwake -s $((10 * 60)) -m disk
>                 sleep 500
>         done
> 
> If there are many RTC utilities out there that aren't x86-specific, I didn't
> happen to find them.  Ergo this one.

Your new RTC driver seems to work for me (thinkpad x60), but no, I
can't get wakeup using RTC to work:

root@amd:~# echo HDEF > /proc/acpi/wakeup
root@amd:~# cat /proc/acpi/wakeup
Device  Sleep state     Status
 LID       3            * enabled
SLPB       3            * enabled
DURT       3             enabled
EXP0       4             enabled
EXP1       4             enabled
EXP2       4             enabled
EXP3       4             enabled
PCI1       4             enabled
USB0       3             enabled
USB1       3             enabled
USB2       3             enabled
USB7       3             enabled
HDEF       4             enabled
root@amd:~# sync
root@amd:~# sync; /tmp/rtcwake -s $((2 * 60)) -m disk
rtcwake: wakeup from "disk" using rtc0 at Sun Aug 27 16:54:49 2006
root@amd:~#

Any ideas? (I tried suspending to RAM, too; no change).

Is acpi-rtc code likely to be merged?
							Pavel

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

Re: waking system up using RTC (was Re: rtcwakeup.c)

[David Brownell]

On Saturday 26 August 2006 7:59 am, Pavel Machek wrote:

> Your new RTC driver seems to work for me (thinkpad x60), but no, I
> can't get wakeup using RTC to work:

Does it work using /proc/acpi/alarm?  In my experience, ACPI wakeup
doesn't work on Linux ... hence my pleasant surprise to see it work
at last, albeit just with the RTC, on every system I tried.  (That's
using swsusp; and on the system where STR works, also STR.)

Of course, as you noted by implication, RTC wake does not involve the
mechanisms exposed by /proc/acpi/wakeup ... that surely helps.


However:

> root@amd:~# sync; /tmp/rtcwake -s $((2 * 60)) -m disk
> rtcwake: wakeup from "disk" using rtc0 at Sun Aug 27 16:54:49 2006
> root@amd:~#

That's what it should look like -- with "date" immediately after rtcwake
returns showing some time after 16:54.  That is, assuming your system
can suspend in 2 minutes ... current versions of swsusp seem to take almost
that long to write snapshots for me, on two different systems with 1GB
of RAM, so I've taken to doing "-m disk" tests with 5 minute sleeps.

So you're sure it didn't actually suspend, right?


> Any ideas? (I tried suspending to RAM, too; no change).

An updated rtcwake.c is appended, which is a bit pickier about noticing
when the write to /sys/power/state fails ... the original code was lazy
and used fwrite(), which isn't as good about fault reporting.  (I'll just
assume STR works properly on your system -- a pleasant rarity!)

So for example, check dmesg output to see if the suspend worked; the
older version of rtcwake wouldn't have noticed errors if it failed
because e.g. one driver refused to suspend.  This one should notice
and report them.

There could also be BIOS issues; folk keep mentioning issues that are
specific to the x60.  Make sure you didn't disable RTC wake there,
and that the RTC reported something like

  rtc-acpi 00:06: AT compatible RTC (S4wake) (y3k), 1 year alarm

at boot time ... if it doesn't report S4 wake capability, or you're
not actually using S4, I'd expect rtc wakeup wouldn't work except
from "real" suspend states (S1/standby, S3/STR).


> Is acpi-rtc code likely to be merged?

Likely not in its current form.  I'll post an updated version soonish,
which doesn't depend so much on PNPACPI.  One issue is how to to have
coupling to ACPI be cleaner.

- Dave


#include <stdio.h>
#include <getopt.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <time.h>

#include <sys/ioctl.h>
#include <sys/time.h>
#include <sys/types.h>

#include <linux/rtc.h>

//#define	DEBUG


/*
 * rtcwake -- enter a system sleep state until specified wakeup time.
 *
 * This uses cross-platform Linux interfaces to enter a system sleep state,
 * and leave it no later than a specified time.  It uses any RTC framework
 * driver that supports standard driver model wakeup flags.
 *
 * This is normally used like the old "apmsleep" utility, to wake from a
 * suspend state like ACPI S1 (standby) or S3 (suspend-to-RAM).  Most
 * platforms can implement those without analogues of BIOS, APM, or ACPI.
 *
 * On some systems, this can also be used like "nvram-wakeup", waking
 * from states like ACPI S4 (suspend to disk).  Not all systems have
 * persistent media that are appropriate for such suspend modes.
 */

static char		*progname;

#ifdef	DEBUG
#define	VERSION	"1.0 dev (" __DATE__ " " __TIME__ ")"
#else
#define	VERSION	"0.9"
#endif

static unsigned		verbose;

static int may_wakeup(const char *devname)
{
	char	buf[128], *s;
	FILE	*f;

	snprintf(buf, sizeof buf, "/sys/class/rtc/%s/device/power/wakeup",
			devname);
	f = fopen(buf, "r");
	if (!f) {
		perror(buf);
		return 0;
	}
	fgets(buf, sizeof buf, f);
	fclose(f);

	s = strchr(buf, '\n');
	if (!s)
		return 0;
	*s = 0;

	/* wakeup events could be disabled or not supported */
	return strcmp(buf, "enabled") == 0;
}

/* all times should be in UTC */
static time_t	sys_time;
static time_t	rtc_time;

static int get_basetimes(int fd)
{
	struct tm	tm;
	time_t		offset;
	struct rtc_time	rtc;

	/* record offset of mktime(), so we can reverse it */
	memset(&tm, 0, sizeof tm);
	tm.tm_year = 70;
	offset = mktime(&tm);

	/* read system and rtc clocks "at the same time"; both in UTC */
	sys_time = time(0);
	if (sys_time == (time_t)-1) {
		perror("read system time");
		return 0;
	}
	if (ioctl(fd, RTC_RD_TIME, &rtc) < 0) {
		perror("read rtc time");
		return 0;
	}

	/* convert rtc_time to normal arithmetic-friendly form */
	tm.tm_sec = rtc.tm_sec;
	tm.tm_min = rtc.tm_min;
	tm.tm_hour = rtc.tm_hour;
	tm.tm_mday = rtc.tm_mday;
	tm.tm_mon = rtc.tm_mon;
	tm.tm_year = rtc.tm_year;
	tm.tm_wday = rtc.tm_wday;
	tm.tm_yday = rtc.tm_yday;
	tm.tm_isdst = rtc.tm_isdst;

	if (verbose) {
		printf("\toffset  = %ld\n", offset);
		printf("\tsystime = %s", asctime(gmtime(&sys_time)));
		printf("\trtctime = %s", asctime(&tm));
	}

	rtc_time = mktime(&tm) - offset;
	if (rtc_time == (time_t)-1) {
		perror("convert rtc time");
		return 0;
	}

	return 1;
}

static int setup_alarm(int fd, time_t *wakeup)
{
	struct tm		*tm;
	struct rtc_wkalrm	wake;

	tm = gmtime(wakeup);

	wake.time.tm_sec = tm->tm_sec;
	wake.time.tm_min = tm->tm_min;
	wake.time.tm_hour = tm->tm_hour;
	wake.time.tm_mday = tm->tm_mday;
	wake.time.tm_mon = tm->tm_mon;
	wake.time.tm_year = tm->tm_year;
	wake.time.tm_wday = tm->tm_wday;
	wake.time.tm_yday = tm->tm_yday;
	wake.time.tm_isdst = tm->tm_isdst;

	/* many rtc alarms only support up to 24 hours from 'now' ... */
	if ((rtc_time + 24 * 60 * 60) > *wakeup) {
		if (ioctl(fd, RTC_ALM_SET, &wake.time) < 0) {
			perror("set rtc alarm");
			return 0;
		}
		if (ioctl(fd, RTC_AIE_ON, 0) < 0) {
			perror("enable rtc alarm");
			return 0;
		}

	/* ... so use the "more than 24 hours" request only if we must */
	} else {
		/* avoid an extra AIE_ON call */
		wake.enabled = 1;

		if (ioctl(fd, RTC_WKALM_SET, &wake) < 0) {
			perror("set rtc wake alarm");
			return 0;
		}
	}

	return 1;
}

static void suspend_system(const char *suspend)
{
	char	buf[20];
	int	f = open("/sys/power/state", O_WRONLY);
	int	len;
	ssize_t	n;

	if (f < 0) {
		perror("open /sys/power/state");
		return;
	}

	len = sprintf(buf, "%s\n", suspend) - 1;
	len = strlen(buf);
	n = write(f, buf, len);

	/* this executes after wake from suspend */
	if (n < 0)
		perror("write /sys/power/state");
	else if (n != len)
		fprintf(stderr, "short write to %s\n", "/sys/power/state");
	close(f);
}

int main(int argc, char **argv)
{
	static char		*devname = "rtc0";
	static unsigned		seconds = 0;
	static char		*suspend = "standby";

	int		t;
	int		fd;
	time_t		alarm = 0;

	progname = strrchr(argv[0], '/');
	if (progname)
		progname++;
	else
		progname = argv[0];
	if (chdir("/dev/") < 0) {
		perror("chdir /dev");
		return 1;
	}

	while ((t = getopt(argc, argv, "d:m:s:t:Vv")) != EOF) {
		switch (t) {

		case 'd':
			devname = optarg;
			break;

		/* what system power mode to use?  for now handle only
		 * standardized mode names; eventually when systems define
		 * their own state names, parse /sys/power/state.
		 *
		 * "on" is used just to test the RTC alarm mechanism,
		 * bypassing all the wakeup-from-sleep infrastructure.
		 */
		case 'm':
			if (strcmp(optarg, "standby") == 0
					|| strcmp(optarg, "mem") == 0
					|| strcmp(optarg, "disk") == 0
					|| strcmp(optarg, "on") == 0
					) {
				suspend = optarg;
				break;
			}
			printf("%s: unrecognized suspend state '%s'\n",
					progname, optarg);
			goto usage;

		/* alarm time, seconds-to-sleep (relative) */
		case 's':
			t = atoi(optarg);
			if (t < 0) {
				printf("%s: illegal interval %s seconds\n",
						progname, optarg);
				goto usage;
			}
			seconds = t;
			break;

		/* alarm time, time_t (absolute, seconds since 1/1 1970 UTC) */
		case 't':
			t = atoi(optarg);
			if (t < 0) {
				printf("%s: illegal time_t value %s\n",
						progname, optarg);
				goto usage;
			}
			alarm = t;
			break;

		case 'v':
			verbose++;
			break;

		case 'V':
			printf("%s: version %s\n", progname, VERSION);
			break;

		default:
usage:
			printf("usage: %s [options]"
				"\n\t"
				"-d rtc0|rtc1|...\t(select rtc)"
				"\n\t"
				"-m standby|mem|...\t(sleep mode)"
				"\n\t"
				"-s seconds\t\t(seconds to sleep)"
				"\n\t"
				"-t time_t\t\t(time to wake)"
				"\n\t"
				"-v\t\t\t(verbose messages)"
				"\n\t"
				"-V\t\t\t(show version)"
				"\n",
				progname);
			return 1;
		}
	}

	if (!alarm && !seconds) {
		printf("%s: must provide wake time\n", progname);
		goto usage;
	}

	/* this RTC must exist and (if we'll sleep) be wakeup-enabled */
	fd = open(devname, O_RDONLY);
	if (fd < 0) {
		perror(devname);
		return 1;
	}
	if (strcmp(suspend, "on") != 0 && !may_wakeup(devname)) {
		printf("%s: %s not enabled for wakeup events\n",
				progname, devname);
		return 1;
	}

	/* relative or absolute alarm time, normalized to time_t */
	if (!get_basetimes(fd))
		return 1;
	if (verbose)
		printf("alarm %ld, sys_time %ld, rtc_time %ld, seconds %u\n",
				alarm, sys_time, rtc_time, seconds);
	if (alarm) {
		if (alarm < sys_time) {
			printf("%s: time doesn't go backward to %s",
					progname, ctime(&alarm));
			return 1;
		}
		alarm += sys_time - rtc_time;
	} else
		alarm = rtc_time + seconds + 1;
	if (!setup_alarm(fd, &alarm))
		return 1;

	printf("%s: wakeup from \"%s\" using %s at %s",
			progname, suspend, devname,
			ctime(&alarm));
	fflush(stdout);
	usleep(10 * 1000);

	if (strcmp(suspend, "on") != 0)
		suspend_system(suspend);
	else {
		unsigned long data;

		(void) read(fd, &data, sizeof data);
	}

	if (ioctl(fd, RTC_AIE_OFF, 0) < 0)
		perror("disable rtc alarm interrupt");

	close(fd);
	return 0;
}

Re: waking system up using RTC (was Re: rtcwakeup.c)

[Pavel Machek]

Hi!

> > Your new RTC driver seems to work for me (thinkpad x60), but no, I
> > can't get wakeup using RTC to work:
> 
> Does it work using /proc/acpi/alarm?  In my experience, ACPI wakeup
> doesn't work on Linux ... hence my pleasant surprise to see it work

No, I could not get it working using /proc/acpi/alarm.

> at last, albeit just with the RTC, on every system I tried.  (That's
> using swsusp; and on the system where STR works, also STR.)

Both swsusp and STR work here.

> However:
> 
> > root@amd:~# sync; /tmp/rtcwake -s $((2 * 60)) -m disk
> > rtcwake: wakeup from "disk" using rtc0 at Sun Aug 27 16:54:49 2006
> > root@amd:~#
> 
> That's what it should look like -- with "date" immediately after rtcwake
> returns showing some time after 16:54.  That is, assuming your system
> can suspend in 2 minutes ... current versions of swsusp seem to take almost
> that long to write snapshots for me, on two different systems with 1GB
> of RAM, so I've taken to doing "-m disk" tests with 5 minute sleeps.
> 
> So you're sure it didn't actually suspend, right?

It *did* suspend, but I had to wake it up manually using power button.

> > Any ideas? (I tried suspending to RAM, too; no change).
> 
> An updated rtcwake.c is appended, which is a bit pickier about noticing
> when the write to /sys/power/state fails ... the original code was lazy
> and used fwrite(), which isn't as good about fault reporting.

No, machine actually suspends okay, it just does not wake up :-(.

>  (I'll just
> assume STR works properly on your system -- a pleasant rarity!)

Yes, it works for me, and if you install code from suspend.sf.net, it
will work for you, too :-) [probably, we have 90% or so success rate].

> There could also be BIOS issues; folk keep mentioning issues that are
> specific to the x60.  Make sure you didn't disable RTC wake there,
> and that the RTC reported something like
> 
>   rtc-acpi 00:06: AT compatible RTC (S4wake) (y3k), 1 year alarm

It says:

rtc-acpi 00:07: AT compatible RTC (S4wake) (y3k), 1 month alarm

> at boot time ... if it doesn't report S4 wake capability, or you're
> not actually using S4, I'd expect rtc wakeup wouldn't work except
> from "real" suspend states (S1/standby, S3/STR).


...but I'm not sure if I was using right swsusp mode (platform
vs. shutdown).

Thanks for help,
								Pavel

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

Re: waking system up using RTC (was Re: rtcwakeup.c)

[David Brownell]

On Saturday 26 August 2006 2:43 pm, Pavel Machek wrote:
> Hi!
> 
> > > Your new RTC driver seems to work for me (thinkpad x60), but no, I
> > > can't get wakeup using RTC to work:
> > 
> > Does it work using /proc/acpi/alarm?  In my experience, ACPI wakeup
> > doesn't work on Linux ... hence my pleasant surprise to see it work
> 
> No, I could not get it working using /proc/acpi/alarm.

Then I suspect that's the root cause of your problem ... ACPI code,
in either Linux or your BIOS, is not sufficiently cooperative.  All
that the rtc-acpi driver does is move the wakeup code, it doesn't
actually change what the /proc/acpi/alarm stuff does.


> No, machine actually suspends okay, it just does not wake up :-(.

The usual ACPI wakeup symptoms I've seen are the hardware giving the
signal, system starting to wake up, then botching somewhere early in
the resum.  So I suspect you're not actually getting the hardware
wakeup signal ... as if maybe it wasn't set up correctly.

You may be able to tell your BIOS to do the alarm by itself, and
then test to see whether Linux handles the wakeup side OK.


> rtc-acpi 00:07: AT compatible RTC (S4wake) (y3k), 1 month alarm

Seems like Intel's chips won't do one year alarms ... so sad.  :)

- Dave

Re: waking system up using RTC (was Re: rtcwakeup.c)

[Pavel Machek]

Hi!

> > > > Your new RTC driver seems to work for me (thinkpad x60), but no, I
> > > > can't get wakeup using RTC to work:
> > > 
> > > Does it work using /proc/acpi/alarm?  In my experience, ACPI wakeup
> > > doesn't work on Linux ... hence my pleasant surprise to see it work
> > 
> > No, I could not get it working using /proc/acpi/alarm.
> 
> Then I suspect that's the root cause of your problem ... ACPI code,
> in either Linux or your BIOS, is not sufficiently cooperative.  All
> that the rtc-acpi driver does is move the wakeup code, it doesn't
> actually change what the /proc/acpi/alarm stuff does.

I searched the bios; timer wakeup is enabled, but I can't set timer
wakeup from the bios.

> > rtc-acpi 00:07: AT compatible RTC (S4wake) (y3k), 1 month alarm
> 
> Seems like Intel's chips won't do one year alarms ... so sad.  :)

:-).

(BTW... if STR still does not work on your notebook, let me know, and
we can try to fix that...)
								Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html