alarmtimer suspend return -EBUSY if the next alarm will fire in less
than 2 seconds. This allows one RTC seconds tick to occur subsequent
to this check before the alarm wakeup time is set, ensuring the wakeup
time is still in the future (assuming the RTC does not tick one more
second prior to setting the alarm).
If suspend is rejected due to an imminent alarm, hold a wakeup source
for 2 seconds to process the alarm prior to reattempting suspend.
If setting the alarm incurs an -ETIME for an alarm set in the past,
or any other problem setting the alarm, abort suspend and hold a
wakelock for 1 second while the alarm is allowed to be serviced or
other hopefully transient conditions preventing the alarm clear up.
Signed-off-by: Todd Poynor <[email protected]>
---
kernel/time/alarmtimer.c | 18 +++++++++++++-----
1 files changed, 13 insertions(+), 5 deletions(-)
diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
index aa27d39..f979d85 100644
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -46,6 +46,8 @@ static struct alarm_base {
static ktime_t freezer_delta;
static DEFINE_SPINLOCK(freezer_delta_lock);
+static struct wakeup_source *ws;
+
#ifdef CONFIG_RTC_CLASS
/* rtc timer and device for setting alarm wakeups at suspend */
static struct rtc_timer rtctimer;
@@ -250,6 +252,7 @@ static int alarmtimer_suspend(struct device *dev)
unsigned long flags;
struct rtc_device *rtc;
int i;
+ int ret;
spin_lock_irqsave(&freezer_delta_lock, flags);
min = freezer_delta;
@@ -279,8 +282,10 @@ static int alarmtimer_suspend(struct device *dev)
if (min.tv64 == 0)
return 0;
- /* XXX - Should we enforce a minimum sleep time? */
- WARN_ON(min.tv64 < NSEC_PER_SEC);
+ if (ktime_to_ns(min) < 2 * NSEC_PER_SEC) {
+ __pm_wakeup_event(ws, 2 * MSEC_PER_SEC);
+ return -EBUSY;
+ }
/* Setup an rtc timer to fire that far in the future */
rtc_timer_cancel(rtc, &rtctimer);
@@ -288,9 +293,11 @@ static int alarmtimer_suspend(struct device *dev)
now = rtc_tm_to_ktime(tm);
now = ktime_add(now, min);
- rtc_timer_start(rtc, &rtctimer, now, ktime_set(0, 0));
-
- return 0;
+ /* Set alarm, if in the past reject suspend briefly to handle */
+ ret = rtc_timer_start(rtc, &rtctimer, now, ktime_set(0, 0));
+ if (ret < 0)
+ __pm_wakeup_event(ws, 1 * MSEC_PER_SEC);
+ return ret;
}
#else
static int alarmtimer_suspend(struct device *dev)
@@ -821,6 +828,7 @@ static int __init alarmtimer_init(void)
error = PTR_ERR(pdev);
goto out_drv;
}
+ ws = wakeup_source_register("alarmtimer");
return 0;
out_drv:
--
1.7.7.3
On Thursday, August 09, 2012, Todd Poynor wrote:
> alarmtimer suspend return -EBUSY if the next alarm will fire in less
> than 2 seconds. This allows one RTC seconds tick to occur subsequent
> to this check before the alarm wakeup time is set, ensuring the wakeup
> time is still in the future (assuming the RTC does not tick one more
> second prior to setting the alarm).
>
> If suspend is rejected due to an imminent alarm, hold a wakeup source
> for 2 seconds to process the alarm prior to reattempting suspend.
>
> If setting the alarm incurs an -ETIME for an alarm set in the past,
> or any other problem setting the alarm, abort suspend and hold a
> wakelock for 1 second while the alarm is allowed to be serviced or
> other hopefully transient conditions preventing the alarm clear up.
>
> Signed-off-by: Todd Poynor <[email protected]>
> ---
> kernel/time/alarmtimer.c | 18 +++++++++++++-----
> 1 files changed, 13 insertions(+), 5 deletions(-)
>
> diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
> index aa27d39..f979d85 100644
> --- a/kernel/time/alarmtimer.c
> +++ b/kernel/time/alarmtimer.c
> @@ -46,6 +46,8 @@ static struct alarm_base {
> static ktime_t freezer_delta;
> static DEFINE_SPINLOCK(freezer_delta_lock);
>
> +static struct wakeup_source *ws;
> +
> #ifdef CONFIG_RTC_CLASS
> /* rtc timer and device for setting alarm wakeups at suspend */
> static struct rtc_timer rtctimer;
> @@ -250,6 +252,7 @@ static int alarmtimer_suspend(struct device *dev)
> unsigned long flags;
> struct rtc_device *rtc;
> int i;
> + int ret;
>
> spin_lock_irqsave(&freezer_delta_lock, flags);
> min = freezer_delta;
> @@ -279,8 +282,10 @@ static int alarmtimer_suspend(struct device *dev)
> if (min.tv64 == 0)
> return 0;
>
> - /* XXX - Should we enforce a minimum sleep time? */
> - WARN_ON(min.tv64 < NSEC_PER_SEC);
> + if (ktime_to_ns(min) < 2 * NSEC_PER_SEC) {
> + __pm_wakeup_event(ws, 2 * MSEC_PER_SEC);
> + return -EBUSY;
> + }
>
> /* Setup an rtc timer to fire that far in the future */
> rtc_timer_cancel(rtc, &rtctimer);
> @@ -288,9 +293,11 @@ static int alarmtimer_suspend(struct device *dev)
> now = rtc_tm_to_ktime(tm);
> now = ktime_add(now, min);
>
> - rtc_timer_start(rtc, &rtctimer, now, ktime_set(0, 0));
> -
> - return 0;
> + /* Set alarm, if in the past reject suspend briefly to handle */
> + ret = rtc_timer_start(rtc, &rtctimer, now, ktime_set(0, 0));
> + if (ret < 0)
> + __pm_wakeup_event(ws, 1 * MSEC_PER_SEC);
Why not just MSEC_PER_SEC?
> + return ret;
> }
> #else
> static int alarmtimer_suspend(struct device *dev)
> @@ -821,6 +828,7 @@ static int __init alarmtimer_init(void)
> error = PTR_ERR(pdev);
> goto out_drv;
> }
> + ws = wakeup_source_register("alarmtimer");
> return 0;
>
> out_drv:
>
On 08/09/2012 12:37 AM, Todd Poynor wrote:
> @@ -288,9 +293,11 @@ static int alarmtimer_suspend(struct device *dev)
> now = rtc_tm_to_ktime(tm);
> now = ktime_add(now, min);
>
> - rtc_timer_start(rtc, &rtctimer, now, ktime_set(0, 0));
> -
> - return 0;
> + /* Set alarm, if in the past reject suspend briefly to handle */
> + ret = rtc_timer_start(rtc, &rtctimer, now, ktime_set(0, 0));
> + if (ret < 0)
> + __pm_wakeup_event(ws, 1 * MSEC_PER_SEC);
> + return ret;
What if something other then -ETIME is returned from rtc_timer_start?
thanks
-john
On 08/09/2012 02:06 PM, John Stultz wrote:
> On 08/09/2012 12:37 AM, Todd Poynor wrote:
>> @@ -288,9 +293,11 @@ static int alarmtimer_suspend(struct device *dev)
>> now = rtc_tm_to_ktime(tm);
>> now = ktime_add(now, min);
>>
>> - rtc_timer_start(rtc, &rtctimer, now, ktime_set(0, 0));
>> -
>> - return 0;
>> + /* Set alarm, if in the past reject suspend briefly to handle */
>> + ret = rtc_timer_start(rtc, &rtctimer, now, ktime_set(0, 0));
>> + if (ret < 0)
>> + __pm_wakeup_event(ws, 1 * MSEC_PER_SEC);
>> + return ret;
>
> What if something other then -ETIME is returned from rtc_timer_start?
Bah, sorry, too fast on the trigger there (enlightenment somehow only
comes with clicking the send button).
I see the wakeup_source will expire after a second and the next suspend
can try again.
thanks
-john
On 08/09/2012 12:37 AM, Todd Poynor wrote:
> alarmtimer suspend return -EBUSY if the next alarm will fire in less
> than 2 seconds. This allows one RTC seconds tick to occur subsequent
> to this check before the alarm wakeup time is set, ensuring the wakeup
> time is still in the future (assuming the RTC does not tick one more
> second prior to setting the alarm).
>
> If suspend is rejected due to an imminent alarm, hold a wakeup source
> for 2 seconds to process the alarm prior to reattempting suspend.
>
> If setting the alarm incurs an -ETIME for an alarm set in the past,
> or any other problem setting the alarm, abort suspend and hold a
> wakelock for 1 second while the alarm is allowed to be serviced or
> other hopefully transient conditions preventing the alarm clear up.
>
> Signed-off-by: Todd Poynor <[email protected]>
> ---
> kernel/time/alarmtimer.c | 18 +++++++++++++-----
> 1 files changed, 13 insertions(+), 5 deletions(-)
Thanks for sending this in!
I've gone ahead and queued it for 3.7 (with the minor tweak Rafael
suggested). I'll try to do some further testing of the edge case this
handles as well.
thanks again,
-john
On Thu, Aug 9, 2012 at 2:27 PM, John Stultz <[email protected]> wrote:
> On 08/09/2012 12:37 AM, Todd Poynor wrote:
>>
>> alarmtimer suspend return -EBUSY if the next alarm will fire in less
>> than 2 seconds. This allows one RTC seconds tick to occur subsequent
>> to this check before the alarm wakeup time is set, ensuring the wakeup
>> time is still in the future (assuming the RTC does not tick one more
>> second prior to setting the alarm).
>>
>> If suspend is rejected due to an imminent alarm, hold a wakeup source
>> for 2 seconds to process the alarm prior to reattempting suspend.
>>
>> If setting the alarm incurs an -ETIME for an alarm set in the past,
>> or any other problem setting the alarm, abort suspend and hold a
>> wakelock for 1 second while the alarm is allowed to be serviced or
>> other hopefully transient conditions preventing the alarm clear up.
>>
>> Signed-off-by: Todd Poynor <[email protected]>
>> ---
>> kernel/time/alarmtimer.c | 18 +++++++++++++-----
>> 1 files changed, 13 insertions(+), 5 deletions(-)
>
>
> Thanks for sending this in!
> I've gone ahead and queued it for 3.7 (with the minor tweak Rafael
> suggested). I'll try to do some further testing of the edge case this
> handles as well.
>
You may want to add a wakeupsource to the rtc_timer interface as well.
In the version of the code I have it does not look like
rtc_timer_start will ever return -ETIME. rtc_timer_enqueue swallows
that error code and schedules work instead.
--
Arve Hj?nnev?g