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From: Alexandre Belloni <alexandre.belloni@free-electrons.com>
To: Colin King <colin.king@canonical.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>,
	rtc-linux@googlegroups.com, linux-kernel@vger.kernel.org
Subject: [rtc-linux] Re: [PATCH] rtc: interface: ignore exprired timers one enqueing new timers
Date: Thu, 19 May 2016 18:38:22 +0200	[thread overview]
Message-ID: <20160519163822.GI2890@piout.net> (raw)
In-Reply-To: <1463415774-28014-1-git-send-email-colin.king@canonical.com>

Hi Colin,

On 16/05/2016 at 17:22:54 +0100, Colin King wrote :
> From: Colin Ian King <colin.king@canonical.com>
> 
> 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 repead 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>

Thanks for the resend. I was still planning to have a look at the patch
you send in September 2014. I believe that one replaces it.

I'll definitely have a look after 4.7-rc1.


-- 
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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WARNING: multiple messages have this Message-ID (diff)
From: Alexandre Belloni <alexandre.belloni@free-electrons.com>
To: Colin King <colin.king@canonical.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>,
	rtc-linux@googlegroups.com, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] rtc: interface: ignore exprired timers one enqueing new timers
Date: Thu, 19 May 2016 18:38:22 +0200	[thread overview]
Message-ID: <20160519163822.GI2890@piout.net> (raw)
In-Reply-To: <1463415774-28014-1-git-send-email-colin.king@canonical.com>

Hi Colin,

On 16/05/2016 at 17:22:54 +0100, Colin King wrote :
> From: Colin Ian King <colin.king@canonical.com>
> 
> 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 repead 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>

Thanks for the resend. I was still planning to have a look at the patch
you send in September 2014. I believe that one replaces it.

I'll definitely have a look after 4.7-rc1.


-- 
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

  reply	other threads:[~2016-05-19 16:38 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-05-16 16:22 [rtc-linux] [PATCH] rtc: interface: ignore exprired timers one enqueing new timers Colin King
2016-05-16 16:22 ` Colin King
2016-05-19 16:38 ` Alexandre Belloni [this message]
2016-05-19 16:38   ` Alexandre Belloni
2016-06-04 13:27 ` [rtc-linux] " Alexandre Belloni
2016-06-04 13:27   ` Alexandre Belloni

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