linux-kernel - [PATCH V3 0/2] rtc-cmos: Workaround unwanted interrupt generation

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Date:	Tue, 16 Aug 2016 08:55:42 +0530
From:	Pratyush Anand <panand@...hat.com>
To:	mingo@...nel.org, alexandre.belloni@...e-electrons.com,
	tglx@...utronix.de, hpa@...or.com, x86@...nel.org
Cc:	rtc-linux@...glegroups.com, linux-kernel@...r.kernel.org,
	prarit@...hat.com, dzickus@...hat.com, dyoung@...hat.com,
	a.zummo@...ertech.it, Pratyush Anand <panand@...hat.com>
Subject: [PATCH V3 0/2] rtc-cmos: Workaround unwanted interrupt generation

We have observed on few machines with rtc-cmos devices that it generates
an interrupt before the hpet_rtc_timer_init() call is finished. This leads
to hpet_rtc_interrupt() being called before it is fully initialized.

Therefore the while-loop of hpet_cnt_ahead() in hpet_rtc_timer_reinit()
never completes. This leads to "NMI watchdog: Watchdog detected hard LOCKUP
on cpu 0".

This patch set initializes hpet_default_delta and hpet_t1_cmp before
interrupt can be raised.

Changes since V2:
  - Improved commit log further
Changes since RFC:
  - Commit log of patches has been improved.

Pratyush Anand (2):
  rtc/hpet: Factorize hpet_rtc_timer_init()
  rtc/rtc-cmos: Initialize software counters before irq is registered

 arch/x86/include/asm/hpet.h |  2 ++
 arch/x86/kernel/hpet.c      | 41 +++++++++++++++++++++++++++++++++++------
 drivers/rtc/rtc-cmos.c      | 13 ++++++++++++-
 3 files changed, 49 insertions(+), 7 deletions(-)

-- 
2.5.5