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From: Thomas Gleixner <tglx@linutronix.de>
To: Chen Yu <yu.c.chen@intel.com>
Cc: John Stultz <john.stultz@linaro.org>,
	"Rafael J. Wysock" <rjw@rjwysocki.net>,
	Linux PM list <linux-pm@vger.kernel.org>,
	Linux Kernel list <linux-kernel@vger.kernel.org>,
	"Stable # 3 . 17+" <stable@vger.kernel.org>
Subject: Re: [PATCH][v2] timekeeping: Fix memory overwrite of sleep_time_bin array
Date: Tue, 19 Jul 2016 10:36:20 +0200 (CEST)	[thread overview]
Message-ID: <alpine.DEB.2.11.1607191031260.3596@nanos> (raw)
In-Reply-To: <1468903861-12487-1-git-send-email-yu.c.chen@intel.com>

On Tue, 19 Jul 2016, Chen Yu wrote:

> It is reported the hibernation fails at 2nd attempt, which
> hangs at hibernate() -> syscore_resume() -> i8237A_resume()
> -> claim_dma_lock(), because the lock has already been taken.
> However there is actually no other process would like to grab
> this lock on that problematic platform.
> 
> Further investigation shows that, the problem is caused by setting
> /sys/power/pm_trace to 1 before the 1st hibernation, since once
> pm_trace is enabled, the rtc becomes an unmeaningful value after resumed,

So why is the RTC value useless if pm_trace is enabled? I really have a hard
time to understand why pm_trace would affect the sleep time readout from RTC.

Thanks,

	tglx

  reply	other threads:[~2016-07-19  8:36 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-07-19  4:51 [PATCH][v2] timekeeping: Fix memory overwrite of sleep_time_bin array Chen Yu
2016-07-19  8:36 ` Thomas Gleixner [this message]
2016-07-19  9:07   ` Chen Yu
2016-07-19 10:40     ` Thomas Gleixner
2016-07-20 11:06       ` Chen Yu
2016-07-20 12:59         ` Rafael J. Wysocki
2016-07-20 16:59           ` Chen, Yu C
2016-07-29  9:50       ` Chen Yu
2016-07-29 12:59         ` Thomas Gleixner

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