From 1c6b39ad3f01514fd8dd84b5b412bafb75c19388 Mon Sep 17 00:00:00 2001 From: John Stultz Date: Thu, 16 Jun 2011 18:47:37 -0700 Subject: [PATCH] alarmtimers: Return -ENOTSUPP if no RTC device is present MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Toralf Förster and Richard Weinberger noted that if there is no RTC device, the alarm timers core prints out an annoying "ALARM timers will not wake from suspend" message. This warning has been removed in a previous patch, however the issue still remains: The original idea was to support alarm timers even if there was no rtc device, as long as the system didn't go into suspend. However, after further consideration, communicating to the application that alarmtimers are not fully functional seems like the better solution. So this patch makes it so we return -ENOTSUPP to any posix _ALARM clockid calls if there is no backing RTC device on the system. Further this changes the behavior where when there is no rtc device we will check for one on clock_getres, clock_gettime, timer_create, and timer_nsleep instead of on suspend. CC: Toralf Förster CC: Richard Weinberger CC: Thomas Gleixner Reported-by: Toralf Förster Reported by: Richard Weinberger Signed-off-by: John Stultz --- kernel/time/alarmtimer.c | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-) diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c index 98ecf4e36f2f..59f369f98a04 100644 --- a/kernel/time/alarmtimer.c +++ b/kernel/time/alarmtimer.c @@ -107,6 +107,9 @@ static struct rtc_device *alarmtimer_get_rtcdev(void) return ret; } +#else +#define alarmtimer_get_rtcdev() (0) +#define rtcdev (0) #endif @@ -231,7 +234,7 @@ static int alarmtimer_suspend(struct device *dev) freezer_delta = ktime_set(0, 0); spin_unlock_irqrestore(&freezer_delta_lock, flags); - rtc = alarmtimer_get_rtcdev(); + rtc = rtcdev; /* If we have no rtcdev, just return */ if (!rtc) return 0; @@ -381,6 +384,9 @@ static int alarm_clock_getres(const clockid_t which_clock, struct timespec *tp) { clockid_t baseid = alarm_bases[clock2alarm(which_clock)].base_clockid; + if (!alarmtimer_get_rtcdev()) + return -ENOTSUPP; + return hrtimer_get_res(baseid, tp); } @@ -395,6 +401,9 @@ static int alarm_clock_get(clockid_t which_clock, struct timespec *tp) { struct alarm_base *base = &alarm_bases[clock2alarm(which_clock)]; + if (!alarmtimer_get_rtcdev()) + return -ENOTSUPP; + *tp = ktime_to_timespec(base->gettime()); return 0; } @@ -410,6 +419,9 @@ static int alarm_timer_create(struct k_itimer *new_timer) enum alarmtimer_type type; struct alarm_base *base; + if (!alarmtimer_get_rtcdev()) + return -ENOTSUPP; + if (!capable(CAP_WAKE_ALARM)) return -EPERM; @@ -444,6 +456,9 @@ static void alarm_timer_get(struct k_itimer *timr, */ static int alarm_timer_del(struct k_itimer *timr) { + if (!rtcdev) + return -ENOTSUPP; + alarm_cancel(&timr->it.alarmtimer); return 0; } @@ -461,6 +476,9 @@ static int alarm_timer_set(struct k_itimer *timr, int flags, struct itimerspec *new_setting, struct itimerspec *old_setting) { + if (!rtcdev) + return -ENOTSUPP; + /* Save old values */ old_setting->it_interval = ktime_to_timespec(timr->it.alarmtimer.period); @@ -600,6 +618,9 @@ static int alarm_timer_nsleep(const clockid_t which_clock, int flags, int ret = 0; struct restart_block *restart; + if (!alarmtimer_get_rtcdev()) + return -ENOTSUPP; + if (!capable(CAP_WAKE_ALARM)) return -EPERM; -- 2.30.2