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* rtc: clarify the RTC offset correctionRussell King2017-10-251-0/+4
| | | | | | | | | The RTC offset correction documentation is not very clear about the exact relationship between "offset" and the effect it has on the RTC. Supplement the documentation with an equation giving the relationship. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
* rtc: set the alarm to the next expiring timerAlexandre Belloni2017-09-281-1/+1
| | | | | | | | | | | If there is any non expired timer in the queue, the RTC alarm is never set. This is an issue when adding a timer that expires before the next non expired timer. Ensure the RTC alarm is set in that case. Fixes: 2b2f5ff00f63 ("rtc: interface: ignore expired timers when enqueuing new timers") Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
* rtc: interface: Validate alarm-time before handling rolloverVaibhav Jain2017-05-311-1/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In function __rtc_read_alarm() its possible for an alarm time-stamp to be invalid even after replacing missing components with current time-stamp. The condition 'alarm->time.tm_year < 70' will trigger this case and will cause the call to 'rtc_tm_to_time64(&alarm->time)' return a negative value for variable t_alm. While handling alarm rollover this negative t_alm (assumed to seconds offset from '1970-01-01 00:00:00') is converted back to rtc_time via rtc_time64_to_tm() which results in this error log with seemingly garbage values: "rtc rtc0: invalid alarm value: -2-1--1041528741 2005511117:71582844:32" This error was generated when the rtc driver (rtc-opal in this case) returned an alarm time-stamp of '00-00-00 00:00:00' to indicate that the alarm is disabled. Though I have submitted a separate fix for the rtc-opal driver, this issue may potentially impact other existing/future rtc drivers. To fix this issue the patch validates the alarm time-stamp just after filling up the missing datetime components and if rtc_valid_tm() still reports it to be invalid then bails out of the function without handling the rollover. Reported-by: Steve Best <sbest@redhat.com> Signed-off-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
* ktime: Cleanup ktime_set() usageThomas Gleixner2016-12-251-4/+4
| | | | | | | | | | ktime_set(S,N) was required for the timespec storage type and is still useful for situations where a Seconds and Nanoseconds part of a time value needs to be converted. For anything where the Seconds argument is 0, this is pointless and can be replaced with a simple assignment. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org>
* ktime: Get rid of the unionThomas Gleixner2016-12-251-4/+4
| | | | | | | | | | | | | | | ktime is a union because the initial implementation stored the time in scalar nanoseconds on 64 bit machine and in a endianess optimized timespec variant for 32bit machines. The Y2038 cleanup removed the timespec variant and switched everything to scalar nanoseconds. The union remained, but become completely pointless. Get rid of the union and just keep ktime_t as simple typedef of type s64. The conversion was done with coccinelle and some manual mopping up. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org>
* rtc: fix a typo and reduce three empty lines to oneUwe Kleine-König2016-07-111-3/+1
| | | | | Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
* rtc: interface: ignore expired timers when enqueuing new timersColin Ian King2016-06-041-1/+15
| | | | | | | | | | | | | | | | | | | | | | | | | This patch fixes a RTC wakealarm issue, namely, the event fires during hibernate and is not cleared from the list, causing hwclock to block. The current enqueuing does not trigger an alarm if any expired timers already exist on the timerqueue. This can occur when a RTC wake alarm is used to wake a machine out of hibernate and the resumed state has old expired timers that have not been removed from the timer queue. This fix skips over any expired timers and triggers an alarm if there are no pending timers on the timerqueue. Note that the skipped expired timer will get reaped later on, so there is no need to clean it up immediately. The issue can be reproduced by putting a machine into hibernate and waking it with the RTC wakealarm. Running the example RTC test program from tools/testing/selftests/timers/rtctest.c after the hibernate will block indefinitely. With the fix, it no longer blocks after the hibernate resume. BugLink: http://bugs.launchpad.net/bugs/1333569 Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
* rtc: initialize output parameter for read alarm to "uninitialized"Uwe Kleine-König2016-05-301-1/+11
| | | | | | | | | rtc drivers are supposed to set values they don't support to -1. To simplify this for drivers and also make it harder for them to get it wrong initialize the values to -1. Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
* rtc: Add functions to set and read rtc offsetJoshua Clayton2016-03-141-0/+54
| | | | | | | | | | | | | | | | | A number of rtc devices, such as the NXP pcf2123 include a facility to adjust the clock in order to compensate for temperature or a crystal, capacitor, etc, that results in the rtc clock not running at exactly 32.768 kHz. Data sheets I have seen refer to this as a clock offset, and measure it in parts per million, however they often reference ppm to 2 digits of precision, which makes integer ppm less than ideal. We use parts per billion, which more than covers the precision needed and works nicely within 32 bits Signed-off-by: Joshua Clayton <stillcompiling@gmail.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
* rtc: Drop (un)likely before IS_ERR(_OR_NULL)viresh kumar2015-09-051-1/+1
| | | | | | | | | | | | | | IS_ERR(_OR_NULL) already contain an 'unlikely' compiler flag and there is no need to do that again from its callers. Drop it. gemini driver was using likely() for a failure case while the rtc driver is getting registered. That looks wrong and it should really be unlikely. But because we are killing all the unlikely() flags, lets kill that too. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Hans Ulli Kroll <ulli.kroll@googlemail.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
* rtc: interface: Remove rtc_set_mmss()Xunlei Pang2015-06-251-45/+0
| | | | | | | | | Now rtc_set_mmss() has no users, just remove it. We still have rtc_set_time() doing similar things. Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
* rtc: interface: Remove unused return value from rtc_timer_cancel()Krzysztof Kozlowski2015-06-191-3/+1
| | | | | | | | The rtc_timer_cancel() always returns 0 and cannot fail (calls only other void-returning functions). Signed-off-by: Krzysztof Kozlowski <k.kozlowski.k@gmail.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
* drivers/rtc/interface.c: __rtc_read_time: reduce log levelAaro Koskinen2015-04-171-2/+3
| | | | | | | | | | | | | | | | | | | | | __rtc_read_time logs should be debug logs instead of error logs. For example, when the RTC clock is not set, it's not really useful to print a kernel error log every time someone tries to read the clock: ~ # hwclock -r [ 604.508263] rtc rtc0: read_time: fail to read hwclock: RTC_RD_TIME: Invalid argument If there's a real error, it's likely that lower level or higher level code will tell it anyway. Make these logs debug logs, and also print the error code for the read failure. Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi> Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Cc: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* drivers/rtc: Provide y2038 safe rtc_class_ops.set_mmss() replacementXunlei Pang2015-04-031-1/+7
| | | | | | | | | | | | | | | | | | | | | | Currently the rtc_class_op's set_mmss() function takes a 32-bit second value (on 32-bit systems), which is problematic for dates past y2038. This patch provides a safe version named set_mmss64() using y2038 safe time64_t. After this patch, set_mmss() is deprecated and all its users will be fixed to use set_mmss64(), it can be removed when having no users. Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org> [jstultz: Add whitespace fix for checkpatch] Signed-off-by: John Stultz <john.stultz@linaro.org> Acked-by: Alessandro Zummo <a.zummo@towertech.it> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1427945681-29972-8-git-send-email-john.stultz@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* rtc: Update interface.c to use y2038-safe time interfacesXunlei Pang2015-01-241-12/+10
| | | | | | | | | | | | | Currently, interface.c uses y2038 problematic rtc_tm_to_time() and rtc_time_to_tm(). So replace them with their corresponding y2038-safe versions: rtc_tm_to_time64() and rtc_time64_to_tm(). Cc: pang.xunlei <pang.xunlei@linaro.org> Cc: Arnd Bergmann <arnd.bergmann@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org> Signed-off-by: John Stultz <john.stultz@linaro.org>
* rtc: refine rtc_timer_do_work() to consider other set alarm failuresXunlei Pang2014-12-111-0/+13
| | | | | | | | | | | | | | | | | | | | | rtc_timer_do_work() only judges -ETIME failure of__rtc_set_alarm(), but doesn't handle other failures like -EIO, -EBUSY, etc. If there is a failure other than -ETIME, the next rtc_timer will stay in the timerqueue. Then later rtc_timers will be enqueued directly because they have a later expires time, so the alarm irq will never be programmed. When such failures happen, this patch will retry __rtc_set_alarm(), if still can't program the alarm time, it will remove current rtc_timer from timerqueue and fetch next one, thus preventing it from affecting other rtc timers. Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: John Stultz <john.stultz@linaro.org> Cc: Arnd Bergmann <arnd.bergmann@linaro.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* drivers/rtc/interface.c: check the validation of rtc_time in __rtc_read_timeHyogi Gim2014-12-111-0/+8
| | | | | | | | | | | | | | | Some rtc devices always return '0' when rtc_class_ops.read_time is called. So if rtc_time isn't verified in callback, rtc interface cannot know whether rtc_time is valid. Check rtc_time by using 'rtc_valid_tm' in '__rtc_read_time'. And add the message for debugging. Signed-off-by: Hyogi Gim <hyogi.gim@lge.com> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: John Stultz <john.stultz@linaro.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* drivers/rtc/interface.c: check the error after __rtc_read_time()Hyogi Gim2014-08-091-0/+2
| | | | | | | | | | | | | In __rtc_set_alarm(), the error after __rtc_read_time() is not checked. If rtc device fail to read time, we cannot guarantee the following process. Add the verification code for returned __rtc_read_time() error. Signed-off-by: Hyogi Gim <hyogi.gim@lge.com> Acked-by: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* drivers/rtc/interface.c: fix infinite loop in initializing the alarmAles Novak2014-06-071-2/+12
| | | | | | | | | | | | | | | | In __rtc_read_alarm(), if the alarm time retrieved by rtc_read_alarm_internal() from the device contains invalid values (e.g. month=2,mday=31) and the year not set (=-1), the initialization will loop infinitely because the year-fixing loop expects the time being invalid due to leap year. Fix reduces the loop to the leap years and adds final validity check. Signed-off-by: Ales Novak <alnovak@suse.cz> Acked-by: Alessandro Zummo <a.zummo@towertech.it> Reported-by: Jiri Bohac <jbohac@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* rtc: verify a critical argument to rtc_update_irq() before using itAlessandro Zummo2014-04-041-0/+3
| | | | | | | | | | This small addition to the core simplifies code in the drivers and makes them more robust when handling shared IRQs. Signed-off-by: Alessandro Zummo <a.zummo@towertech.it> Cc: Alexander Shiyan <shc_work@mail.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* rtc: Keep system awake until all expired RTC timers are handledZoran Markovic2013-07-221-4/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | Current implementation of RTC interface allows for system suspend to occur in the following cases: (a) if a timer is set in the past and rtc_timer_do_work() is scheduled to handle it, and (b) if rtc_timer_do_work() is called to handle expired timers whose handlers implement a preemption point. A pending suspend request may be honoured in the above cases causing timer handling to be delayed until after the next resume. This is undesirable since timer handlers may have time-critical code to execute. This patch makes sure that the system stays awake until all expired timers are handled. Note that all calls to pm_stay_awake() are eventually paired with the single pm_relax() call in rtc_timer_do_work(), which is launched using schedule_work(). Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: John Stultz <john.stultz@linaro.org> Cc: Arve Hjonnevag <arve@android.com> Cc: Todd Poynor <toddpoynor@google.com> Signed-off-by: Zoran Markovic <zoran.markovic@linaro.org> Signed-off-by: John Stultz <john.stultz@linaro.org>
* drivers/rtc/interface.c: return -EBUSY, not -EACCES when device is busyChris Brand2013-07-041-4/+4
| | | | | | | | | | | If rtc->irq_task is non-NULL and task is NULL, they always rtc_irq_set_freq(), whenever err is set to -EBUSY it will then immediately be set to -EACCES, misleading the caller as to the underlying problem. Signed-off-by: Chris Brand <chris.brand@broadcom.com> Acked-by: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* drivers/rtc/interface.c: fix checkpatch errorsSachin Kamat2013-07-041-9/+9
| | | | | | | | | | | | Fixes the following types of errors: ERROR: "foo* bar" should be "foo *bar" ERROR: else should follow close brace '}' WARNING: braces {} are not necessary for single statement blocks Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org> Cc: Jingoo Han <jg1.han@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* driver-core: constify data for class_find_device()Michał Mirosław2013-02-061-3/+3
| | | | | | | | | | | | | | | | | | All in-kernel users of class_find_device() don't really need mutable data for match callback. In two places (kernel/power/suspend_test.c, drivers/scsi/osd/osd_uld.c) this patch changes match callbacks to use const search data. The const is propagated to rtc_class_open() and power_supply_get_by_name() parameters. Note that there's a dev reference leak in suspend_test.c that's not touched in this patch. Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl> Acked-by: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* RTC: Avoid races between RTC alarm wakeup and suspend.NeilBrown2012-08-081-0/+2
| | | | | | | | | | | | | | | | | | If an RTC alarm fires just as suspend is happening, it is possible for suspend to complete and the alarm to be missed. To avoid the race, we must register the event with the PM core. As the event is made visible to userspace through a thread which is only scheduled by the interrupt, we need a pm_stay_awake/pm_relax pair preventing suspend from the interrupt until the thread completes its work. This makes the pm_wakeup_event() call in cmos_interrupt unnecessary as it provides suspend protection for all RTCs that use rtc_update_irq. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
* rtc: Provide flag for rtc devices that don't support UIEJohn Stultz2012-03-161-0/+5
| | | | | | | | | | | | | | | | | | | Richard Weinberger noticed that on some RTC hardware that doesn't support UIE mode, due to coarse granular alarms (like 1minute resolution), the current virtualized RTC support doesn't properly error out when UIE is enabled. Instead the current code queues an alarm for the next second, but it won't fire until up to a miniute later. This patch provides a generic way to flag this sort of hardware and fixes the issue on the mpc5121 where Richard noticed the problem. CC: stable@vger.kernel.org Reported-by: Richard Weinberger <richard@nod.at> Tested-by: Richard Weinberger <richard@nod.at> Signed-off-by: John Stultz <john.stultz@linaro.org>
* rtc: Disable the alarm in the hardware (v2)Rabin Vincent2012-01-271-2/+13
| | | | | | | | | | | | | | | | | | | | | | | | Currently, the RTC code does not disable the alarm in the hardware. This means that after a sequence such as the one below (the files are in the RTC sysfs), the box will boot up after 2 minutes even though we've asked for the alarm to be turned off. # echo $((`cat since_epoch`)+120) > wakealarm # echo 0 > wakealarm # poweroff Fix this by disabling the alarm when there are no timers to run. The original version of this patch was reverted. This version disables the irq directly instead of setting a disabled timer in the future. Cc: stable@kernel.org Cc: John Stultz <john.stultz@linaro.org> Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com> [Merged in the second revision from Rabin] Signed-off-by: John Stultz <john.stultz@linaro.org>
* rtc: Expire alarms after the time is set. (v2)NeilBrown2012-01-271-0/+4
| | | | | | | | | | | | | | | | | | | | | If the alarm time programming in the rtc is ever in the past, it won't fire, and any other alarm will be queued after it so they won't fire either. So any time that the alarm might be in the past, we need to trigger the irq handler to ensure the old alarm is cleared and the timer queue is fully in the future. This is done whenever the RTC clock is set. This is the second revision of this patch, which was earlier reverted. This version avoids the initialization problem, which is handled by a different patch. Tested-by: Sander Eikelenboom <linux@eikelenboom.it> Signed-off-by: NeilBrown <neilb@suse.de> [Remove problematic initialization change, update commit log, also catch set_mmss case -jstultz] Signed-off-by: John Stultz <john.stultz@linaro.org>
* rtc: Avoid setting alarm to a time in the pastJohn Stultz2012-01-271-1/+10
| | | | | | | | | | | | | | | | In some cases at boot up, the RTC alarm may be set in the past, but still have the enabled flag on. This was causing problems, because we would then enqueue the alarm into the timerqueue, but it would never fire. This would clog up the timerqueue and keep other alarms from working. The fix is to check the alarm against the current rtc time at boot and avoid enqueueing the alarm if it is in the past. Reported-by: NeilBrown <neilb@suse.de> Tested-by: NeilBrown <neilb@suse.de> Tested-by: Sander Eikelenboom <linux@eikelenboom.it> Signed-off-by: John Stultz <john.stultz@linaro.org>
* drivers/rtc/interface.c: fix alarm rollover when day or month is out-of-rangeBen Hutchings2012-01-111-2/+2
| | | | | | | | | | | | | | | | | | | | | | | Commit f44f7f96a20a ("RTC: Initialize kernel state from RTC") introduced a potential infinite loop. If an alarm time contains a wildcard month and an invalid day (> 31), or a wildcard year and an invalid month (>= 12), the loop searching for the next matching date will never terminate. Treat the invalid values as wildcards. Fixes <http://bugs.debian.org/646429>, <http://bugs.debian.org/653331> Reported-by: leo weppelman <leoweppelman@googlemail.com> Reported-by: "P. van Gaans" <mailme667@yahoo.co.uk> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Marcelo Roberto Jimenez <mroberto@cpti.cetuc.puc-rio.br> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <john.stultz@linaro.org> Acked-by: Alessandro Zummo <a.zummo@towertech.it> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Revert "rtc: Expire alarms after the time is set."Linus Torvalds2012-01-041-6/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit 93b2ec0128c431148b216b8f7337c1a52131ef03. The call to "schedule_work()" in rtc_initialize_alarm() happens too early, and can cause oopses at bootup Neil Brown explains why we do it: "If you set an alarm in the future, then shutdown and boot again after that time, then you will end up with a timer_queue node which is in the past. When this happens the queue gets stuck. That entry-in-the-past won't get removed until and interrupt happens and an interrupt won't happen because the RTC only triggers an interrupt when the alarm is "now". So you'll find that e.g. "hwclock" will always tell you that 'select' timed out. So we force the interrupt work to happen at the start just in case." and has a patch that convert it to do things in-process rather than with the worker thread, but right now it's too late to play around with this, so we just revert the patch that caused problems for now. Reported-by: Sander Eikelenboom <linux@eikelenboom.it> Requested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Requested-by: John Stultz <john.stultz@linaro.org> Cc: Neil Brown <neilb@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Revert "rtc: Disable the alarm in the hardware"Linus Torvalds2012-01-041-34/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit c0afabd3d553c521e003779c127143ffde55a16f. It causes failures on Toshiba laptops - instead of disabling the alarm, it actually seems to enable it on the affected laptops, resulting in (for example) the laptop powering on automatically five minutes after shutdown. There's a patch for it that appears to work for at least some people, but it's too late to play around with this, so revert for now and try again in the next merge window. See for example http://bugs.debian.org/652869 Reported-and-bisected-by: Andreas Friedrich <afrie@gmx.net> (Toshiba Tecra) Reported-by: Antonio-M. Corbi Bellot <antonio.corbi@ua.es> (Toshiba Portege R500) Reported-by: Marco Santos <marco.santos@waynext.com> (Toshiba Portege Z830) Reported-by: Christophe Vu-Brugier <cvubrugier@yahoo.fr> (Toshiba Portege R830) Cc: Jonathan Nieder <jrnieder@gmail.com> Requested-by: John Stultz <john.stultz@linaro.org> Cc: stable@kernel.org # for the versions that applied this Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* rtc: Expire alarms after the time is set.NeilBrown2011-12-131-0/+6
| | | | | | | | | | | | | | | | | | | | If the alarm time programming in the rtc is ever in the past, it won't fire, and any other alarm will be queued after it so they won't fire either. So any time that the alarm might be in the past, we need to trigger the irq handler to ensure the old alarm is cleared and the timer queue is fully in the future. This can happen: - when we first initialise the alarm - when we set the time in the rtc. so follow both of these by scheduling the timer work function. CC: stable@kernel.org Signed-off-by: NeilBrown <neilb@suse.de> [Also catch set_mmss case -jstultz] Signed-off-by: John Stultz <john.stultz@linaro.org>
* Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds2011-12-061-10/+34
|\ | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: clockevents: Set noop handler in clockevents_exchange_device() tick-broadcast: Stop active broadcast device when replacing it clocksource: Fix bug with max_deferment margin calculation rtc: Fix some bugs that allowed accumulating time drift in suspend/resume rtc: Disable the alarm in the hardware
| * rtc: Disable the alarm in the hardwareRabin Vincent2011-11-231-10/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, the RTC code does not disable the alarm in the hardware. This means that after a sequence such as the one below (the files are in the RTC sysfs), the box will boot up after 2 minutes even though we've asked for the alarm to be turned off. # echo $((`cat since_epoch`)+120) > wakealarm # echo 0 > wakealarm # poweroff Fix this by disabling the alarm when there are no timers to run. Cc: stable@kernel.org Cc: John Stultz <john.stultz@linaro.org> Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
| * rtc: fix hrtimer deadlockThomas Gleixner2011-07-271-19/+37
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Ben reported a lockup related to rtc. The lockup happens due to: CPU0 CPU1 rtc_irq_set_state() __run_hrtimer() spin_lock_irqsave(&rtc->irq_task_lock) rtc_handle_legacy_irq(); spin_lock(&rtc->irq_task_lock); hrtimer_cancel() while (callback_running); So the running callback never finishes as it's blocked on rtc->irq_task_lock. Use hrtimer_try_to_cancel() instead and drop rtc->irq_task_lock while waiting for the callback. Fix this for both rtc_irq_set_state() and rtc_irq_set_freq(). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reported-by: Ben Greear <greearb@candelatech.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * rtc: limit frequencyThomas Gleixner2011-07-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Due to the hrtimer self rearming mode a user can DoS the machine simply because it's starved by hrtimer events. The RTC hrtimer is self rearming. We really need to limit the frequency to something sensible. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <john.stultz@linaro.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Ben Greear <greearb@candelatech.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * rtc: handle errors correctly in rtc_irq_set_state()Thomas Gleixner2011-07-271-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The code checks the correctness of the parameters, but unconditionally arms/disarms the hrtimer. The result is that a random task might arm/disarm rtc timer and surprise the real owner by either generating events or by stopping them. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <john.stultz@linaro.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Ben Greear <greearb@candelatech.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | rtc: Add module.h to implicit users in drivers/rtcPaul Gortmaker2011-11-011-0/+1
| | | | | | | | | | | | | | | | The module.h was implicitly everywhere, but when we clean that up, the implicit users will compile fail; fix them up in advance. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* | rtc: Limit RTC PIE frequencyThomas Gleixner2011-07-261-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | The RTC pie hrtimer is self rearming. We really need to limit the frequency to something sensible. Thus limit it to the 8192Hz max value from the rtc man documentation Cc: Willy Tarreau <w@1wt.eu> Cc: stable@kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de> [jstultz: slightly reworked to use RTC_MAX_FREQ value] Signed-off-by: John Stultz <john.stultz@linaro.org>
* | rtc: Fix hrtimer deadlockThomas Gleixner2011-07-261-19/+37
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Ben reported a lockup related to rtc. The lockup happens due to: CPU0 CPU1 rtc_irq_set_state() __run_hrtimer() spin_lock_irqsave(&rtc->irq_task_lock) rtc_handle_legacy_irq(); spin_lock(&rtc->irq_task_lock); hrtimer_cancel() while (callback_running); So the running callback never finishes as it's blocked on rtc->irq_task_lock. Use hrtimer_try_to_cancel() instead and drop rtc->irq_task_lock while waiting for the callback. Fix this for both rtc_irq_set_state() and rtc_irq_set_freq(). Cc: stable@kernel.org Reported-by: Ben Greear <greearb@candelatech.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
* | rtc: Handle errors correctly in rtc_irq_set_state()Thomas Gleixner2011-07-261-0/+3
|/ | | | | | | | | | | In rtc_irq_set_state, the code checks the correctness of the parameters, but then goes on to unconditionally arms/disarms the hrtimer. Thus a random task might arm/disarm rtc timer and surprise the real owner by either generating events or by stopping them. Cc: stable@kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
* rtc: Staticize non-exported __rtc_set_alarm()Mark Brown2011-06-021-1/+1
| | | | | | | | It's not referenced outside this file so there's no need for it to be in the global namespace and sparse warns about that. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
* Merge branch 'fortglx/39/tip/timers/rtc' of ↵Thomas Gleixner2011-04-131-0/+26
|\ | | | | | | git://git.linaro.org/people/jstultz/linux into timers/urgent
| * RTC: Fix early irqs caused by calling rtc_set_alarm too earlyJohn Stultz2011-03-301-0/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When we register an rtc device at boot, we read the alarm value in hardware and set the rtc device's aie_timer to that value. The initial method to do this was to simply call rtc_set_alarm() with the value read from hardware. However, this may cause problems as rtc_set_alarm may enable interupts, and the RTC alarm might fire, which can cause invalid pointer dereferencing since the RTC registration is not complete. This patch solves the issue by initializing the rtc_device.aie_timer y hand via rtc_initialize_alarm(). This avoids any calls to the RTC hardware which might enable interrupts too early. CC: Thomas Gleixner <tglx@linutronix.de> CC: Alessandro Zummo <a.zummo@towertech.it> Reported-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
* | Fix common misspellingsLucas De Marchi2011-03-311-1/+1
|/ | | | | | Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
* RTC: Initialize kernel state from RTCJohn Stultz2011-03-091-0/+180
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Mark Brown pointed out a corner case: that RTC alarms should be allowed to be persistent across reboots if the hardware supported it. The rework of the generic layer to virtualize the RTC alarm virtualized much of the alarm handling, and removed the code used to read the alarm time from the hardware. Mark noted if we want the alarm to be persistent across reboots, we need to re-read the alarm value into the virtualized generic layer at boot up, so that the generic layer properly exposes that value. This patch restores much of the earlier removed rtc_read_alarm code and wires it in so that we set the kernel's alarm value to what we find in the hardware at boot time. NOTE: Not all hardware supports persistent RTC alarm state across system reset. rtc-cmos for example will keep the alarm time, but disables the AIE mode irq. Applications should not expect the RTC alarm to be valid after a system reset. We will preserve what we can, to represent the hardware state at boot, but its not guarenteed. Further, in the future, with multiplexed RTC alarms, the soonest alarm to fire may not be the one set via the /dev/rt ioctls. So an application may set the alarm with RTC_ALM_SET, but after a reset find that RTC_ALM_READ returns an earlier time. Again, we preserve what we can, but applications should not expect the RTC alarm state to persist across a system reset. Big thanks to Mark for pointing out the issue! Thanks also to Marcelo for helping think through the solution. CC: Mark Brown <broonie@opensource.wolfsonmicro.com> CC: Marcelo Roberto Jimenez <mroberto@cpti.cetuc.puc-rio.br> CC: Thomas Gleixner <tglx@linutronix.de> CC: Alessandro Zummo <a.zummo@towertech.it> CC: rtc-linux@googlegroups.com Reported-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
* RTC: Re-enable UIE timer/polling emulationJohn Stultz2011-02-171-1/+17
| | | | | | | | | | | This patch re-enables UIE timer/polling emulation for rtc devices that do not support alarm irqs. CC: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> CC: Thomas Gleixner <tglx@linutronix.de> Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Tested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
* RTC: Release mutex in error path of rtc_alarm_irq_enableUwe Kleine-König2011-02-171-3/+2
| | | | | | | | | | | | | | | | On hardware that doesn't support alarm interrupts, rtc_alarm_irq_enable could return without releasing the ops_lock mutex. This was introduced in aa0be0f (RTC: Propagate error handling via rtc_timer_enqueue properly) This patch corrects the issue by only returning once the mutex is released. [john.stultz: Reworded the commit log] Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
* RTC: Prevents a division by zero in kernel code.Marcelo Roberto Jimenez2011-02-031-0/+3
| | | | | | | | | | | | | | This patch prevents a user space program from calling the RTC_IRQP_SET ioctl with a negative value of frequency. Also, if this call is make with a zero value of frequency, there would be a division by zero in the kernel code. [jstultz: Also initialize irq_freq to 1 to catch other divbyzero issues] CC: Alessandro Zummo <a.zummo@towertech.it> CC: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Marcelo Roberto Jimenez <mroberto@cpti.cetuc.puc-rio.br> Signed-off-by: John Stultz <john.stultz@linaro.org>
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