rtcwake: misc cleanups

Cleanups for rtcwake:

  - Minor doc updates:  highlight the framebuffer problem,
    give correct history of this code
  - Improve debug output
  - Fix some linelength bugs

Note that this code predated the sysfs "wakealarm" mechanism, and
works around several now-fixed bugs in the kernel RTC framework.

Nowadays it would make sense to make this program use only the sysfs
interface to the RTC, using "since_epoch" instead of RTC_RD_TIME and
"wakealarm" instead of the four other ioctls.  That could simplify
the mess involved in timezone handling.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/sys-utils/rtcwake.8 b/sys-utils/rtcwake.8
index dde28441723fe51b943546182821981ffa5a13aa..c06fb2117c5f44b1f27a0aae5732406a4b01ca51 100644 (file)
--- a/sys-utils/rtcwake.8
+++ b/sys-utils/rtcwake.8
@@ -76,15 +76,20 @@ is the time in seconds since 1970-01-01, 00:00 UTC. Use the
 Use standby state \fImode\fP. Valid values are \fIstandby\fP,
 \fImem\fP, \fIdisk\fP and \fIon\fP (no suspend). The default is
 \fIstandby\fP.
+.SH NOTES
+Some PC systems can't currently exit sleep states such as \fImem\fP
+using only the kernel code accessed by this driver.
+They need help from userspace code to make the framebuffer work again.
 .SH HISTORY
-The program first appeared as kernel commit message for Linux 2.6 in the GIT
+The program was posted several times on LKML and other lists
+before appearing in kernel commit message for Linux 2.6 in the GIT
 commit 87ac84f42a7a580d0dd72ae31d6a5eb4bfe04c6d.
 .SH AVAILABILITY
 The rtcwake command is part of the util-linux-ng package and is available from
 ftp://ftp.kernel.org/pub/linux/utils/util-linux-ng/.
 .SH AUTHOR
-The program was written by David Brownell <david-b@pacbell.net> and improved by
-Bernhard Walle <bwalle@suse.de>.
+The program was written by David Brownell <dbrownell@users.sourceforge.net>
+and improved by Bernhard Walle <bwalle@suse.de>.
 .SH COPYRIGHT
 This is free software.  You may redistribute copies of it  under  the  terms
 of  the  GNU General  Public  License <http://www.gnu.org/licenses/gpl.html>.

diff --git a/sys-utils/rtcwake.c b/sys-utils/rtcwake.c
index 092895fecb7298f0492a84dd375e3b693d81f8a4..5fbd6da77d62b3792998b36663f8d2c971f54660 100644 (file)
--- a/sys-utils/rtcwake.c
+++ b/sys-utils/rtcwake.c
@@ -16,6 +16,7 @@
  * The best way to set the system's RTC is so that it holds the current
  * time in UTC.  Use the "-l" flag to tell this program that the system
  * RTC uses a local timezone instead (maybe you dual-boot MS-Windows).
+ * That flag should not be needed on systems with adjtime support.
  */
 
 #include <stdio.h>
@@ -163,14 +164,18 @@ static int get_basetimes(int fd)
        }
 
        if (verbose) {
-               if (clock_mode == CM_LOCAL) {
-                       printf("\ttzone   = %ld\n", timezone);
-                       printf("\ttzname  = %s\n", tzname[daylight]);
-                       gmtime_r(&rtc_time, &tm);
-               }
-               printf("\tsystime = %ld, (UTC) %s\n",
+               /* Unless the system uses UTC, either delta or tzone
+                * reflects a seconds offset from UTC.  The value can
+                * help sort out problems like bugs in your C library.
+                */
+               printf("\tdelta   = %ld\n", sys_time - rtc_time);
+               printf("\ttzone   = %ld\n", timezone);
+
+               printf("\ttzname  = %s\n", tzname[daylight]);
+               gmtime_r(&rtc_time, &tm);
+               printf("\tsystime = %ld, (UTC) %s",
                                (long) sys_time, asctime(gmtime(&sys_time)));
-               printf("\trtctime = %ld, (UTC) %s\n",
+               printf("\trtctime = %ld, (UTC) %s",
                                (long) rtc_time, asctime(&tm));
        }
 
@@ -190,11 +195,14 @@ static int setup_alarm(int fd, time_t *wakeup)
        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;
+       /* wday, yday, and isdst fields are unused by Linux */
+       wake.time.tm_wday = -1;
+       wake.time.tm_yday = -1;
+       wake.time.tm_isdst = -1;
 
-       /* many rtc alarms only support up to 24 hours from 'now' ... */
+       /* many rtc alarms only support up to 24 hours from 'now',
+        * so use the "more than 24 hours" request only if we must
+        */
        if ((rtc_time + (24 * 60 * 60)) > *wakeup) {
                if (ioctl(fd, RTC_ALM_SET, &wake.time) < 0) {
                        perror(_("set rtc alarm"));
@@ -204,8 +212,6 @@ static int setup_alarm(int fd, time_t *wakeup)
                        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;
@@ -321,8 +327,9 @@ int main(int argc, char **argv)
                                suspend = strdup(optarg);
                                break;
                        }
-                       fprintf(stderr, _("%s: unrecognized suspend state '%s'\n"),
-                                       progname, optarg);
+                       fprintf(stderr,
+                               _("%s: unrecognized suspend state '%s'\n"),
+                               progname, optarg);
                        usage(EXIT_FAILURE);
 
                        /* alarm time, seconds-to-sleep (relative) */
@@ -376,10 +383,10 @@ int main(int argc, char **argv)
                        printf(_("%s: assuming RTC uses UTC ...\n"), progname);
                        clock_mode = CM_UTC;
                }
-               if (verbose)
-                       printf(clock_mode == CM_UTC ? _("Using UTC time.\n") :
-                                       _("Using local time.\n"));
        }
+       if (verbose)
+               printf(clock_mode == CM_UTC ? _("Using UTC time.\n") :
+                               _("Using local time.\n"));
 
        if (!alarm && !seconds) {
                fprintf(stderr, _("%s: must provide wake time\n"), progname);
@@ -423,8 +430,9 @@ int main(int argc, char **argv)
                                alarm, sys_time, rtc_time, seconds);
        if (alarm) {
                if (alarm < sys_time) {
-                       fprintf(stderr, _("%s: time doesn't go backward to %s\n"),
-                                       progname, ctime(&alarm));
+                       fprintf(stderr,
+                               _("%s: time doesn't go backward to %s\n"),
+                               progname, ctime(&alarm));
                        exit(EXIT_FAILURE);
                }
                alarm += sys_time - rtc_time;