From: Pratyush Anand <panand@redhat.com>
To: Alexandre Belloni <alexandre.belloni@free-electrons.com>,
Thomas Gleixner <tglx@linutronix.de>,
mingo@kernel.org, hpa@zytor.com, x86@kernel.org
Cc: Alessandro Zummo <a.zummo@towertech.it>,
rtc-linux@googlegroups.com,
open list <linux-kernel@vger.kernel.org>,
Prarit Bhargava <prarit@redhat.com>,
RuiRui Yang <dyoung@redhat.com>
Subject: Re: [PATCH RFC 0/2] rtc-cmos: Workaround unwanted interrupt generation
Date: Wed, 20 Jul 2016 09:26:59 +0530 [thread overview]
Message-ID: <20160720035659.GA4797@localhost.localdomain> (raw)
In-Reply-To: <20160719142907.GG7132@piout.net>
On 19/07/2016:04:29:07 PM, Alexandre Belloni wrote:
> Hi,
>
> On 18/07/2016 at 17:17:44 +0530, Pratyush Anand wrote :
> > Hi RTC-Maintainers,
> >
> >
> > On Mon, Jul 4, 2016 at 9:49 PM, Pratyush Anand <panand@redhat.com> wrote:
> > > On 27/06/2016:10:19:07 AM, Pratyush Anand wrote:
> > >> On 21/06/2016:10:25:34 AM, Pratyush Anand wrote:
> > >> > We have observed on few machines with rtc-cmos device that
> > >> > hpet_rtc_interrupt() is called before cmos_do_probe() could call
> > >> > hpet_rtc_timer_init(). It has not been observed during normal boot/reboot
> > >> > of machines. It *sometime* happens when system is booted with kdump
> > >> > secondary kernel. So, neither hpet_default_delta nor hpet_t1_cmp is
> > >> > initialized by the time interrupt is raised in the given situation.
> > >> > Therefore 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".
> > >> >
> > >> > I am still clueless, how can an interrupt be raised before RTC is enabled.
> > >> > But i do not have any idea about this device, so I am putting this patch as
> > >> > RFC to get feedback from hpet/rtc-cmos developer. I am sure there would be
> > >> > some better solution than this.
> > >>
> > >> Do you think that if I improve commit log of patches as pointed by Thomas and
> > >> send a formal version of these patches, then they should acceptable to upstream?
> > >
> > > A gentle reminder for your comment/feedback :-)
> >
> > Please let me know how to make progress on this. If you think, there
> > could be some better way to handle this issue then please let me know.
> > If you need any more data then also please let me know.
> >
>
> Well, the change is x86 specific and I don't know much about HPET so
> until you get an ack from the x86 maintainers, I guess I can't help
> much.
Thanks Alexandre for your reply.
Thomas, Ingo, Peter, Your comment/feedback will be very helpful to make progress
on this.
~Pratyush
prev parent reply other threads:[~2016-07-20 3:57 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-21 4:55 [PATCH RFC 0/2] rtc-cmos: Workaround unwanted interrupt generation Pratyush Anand
2016-06-21 4:55 ` [PATCH RFC 1/2] rtc/hpet: Factorize hpet_rtc_timer_init() Pratyush Anand
2016-06-23 8:33 ` Thomas Gleixner
2016-06-23 14:37 ` Pratyush Anand
2016-06-21 4:55 ` [PATCH RFC 2/2] rtc/rtc-cmos: Initialize software counters before irq is registered Pratyush Anand
2016-06-27 4:49 ` [PATCH RFC 0/2] rtc-cmos: Workaround unwanted interrupt generation Pratyush Anand
2016-07-04 16:19 ` Pratyush Anand
2016-07-18 11:47 ` Pratyush Anand
2016-07-19 14:29 ` Alexandre Belloni
2016-07-20 3:56 ` Pratyush Anand [this message]
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