Re: [rtc-linux] [patch 2.6.26-rc7] rtc_read_alarm() handles wraparound

[Alessandro Zummo <alessandro.zummo@towertech.it>]

On Sun, 22 Jun 2008 20:42:13 -0700
David Brownell <david-b@pacbell.net> wrote:

> While 0e36a9a4a788e4e92407774df76c545910810d35 made sure that active
> alarms were never returned with invalid "wildcard" fields (negative),
> it can still report (wrongly) that the alarm triggers in the past.
> 
> Example, if it's now 10am, an alarm firing at 5am will be triggered
> TOMORROW not today.  (Which may also be next month or next year...)
> 
> This updates that alarm handling in three ways:
> 
>   * Handle alarm rollover in the common cases of RTCs that don't
>     support matching on all date fields.
> 
>   * Skip the invalid-field logic when it's not needed.
> 
>   * Minor bugfix ... tm_isdst should be ignored, it's one of the
>     fields Linux doesn't maintain.
> 
> A warning is emitted for some of the unhandled rollover cases, but
> the possible combinations are a bit too numerous to handle every
> bit of potential hardware and firmware braindamage.
> 
> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>

 Acked-by: Alessandro Zummo <a.zummo@towertech.it>

-- 

 Best regards,

 Alessandro Zummo,
  Tower Technologies - Torino, Italy

  http://www.towertech.it