From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Sender: rtc-linux@googlegroups.com Received: from mail-pf0-f170.google.com (mail-pf0-f170.google.com. [209.85.192.170]) by gmr-mx.google.com with ESMTPS id a133si77389pfa.0.2016.07.19.20.57.02 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 19 Jul 2016 20:57:02 -0700 (PDT) Received: by mail-pf0-f170.google.com with SMTP id h186so14238834pfg.3 for ; Tue, 19 Jul 2016 20:57:02 -0700 (PDT) Date: Wed, 20 Jul 2016 09:26:59 +0530 From: Pratyush Anand To: Alexandre Belloni , Thomas Gleixner , mingo@kernel.org, hpa@zytor.com, x86@kernel.org Cc: Alessandro Zummo , rtc-linux@googlegroups.com, open list , Prarit Bhargava , RuiRui Yang Subject: [rtc-linux] Re: [PATCH RFC 0/2] rtc-cmos: Workaround unwanted interrupt generation Message-ID: <20160720035659.GA4797@localhost.localdomain> References: <20160627044907.GA29870@dhcppc9> <20160704161948.GB11075@dhcppc9> <20160719142907.GG7132@piout.net> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 In-Reply-To: <20160719142907.GG7132@piout.net> Reply-To: rtc-linux@googlegroups.com List-ID: List-Post: , List-Help: , List-Archive: , List-Unsubscribe: , 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 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 -- You received this message because you are subscribed to "rtc-linux". Membership options at http://groups.google.com/group/rtc-linux . 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From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751237AbcGTD5F (ORCPT ); Tue, 19 Jul 2016 23:57:05 -0400 Received: from mail-pf0-f169.google.com ([209.85.192.169]:35160 "EHLO mail-pf0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751065AbcGTD5E (ORCPT ); Tue, 19 Jul 2016 23:57:04 -0400 Date: Wed, 20 Jul 2016 09:26:59 +0530 From: Pratyush Anand To: Alexandre Belloni , Thomas Gleixner , mingo@kernel.org, hpa@zytor.com, x86@kernel.org Cc: Alessandro Zummo , rtc-linux@googlegroups.com, open list , Prarit Bhargava , RuiRui Yang Subject: Re: [PATCH RFC 0/2] rtc-cmos: Workaround unwanted interrupt generation Message-ID: <20160720035659.GA4797@localhost.localdomain> References: <20160627044907.GA29870@dhcppc9> <20160704161948.GB11075@dhcppc9> <20160719142907.GG7132@piout.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160719142907.GG7132@piout.net> User-Agent: Mutt/1.6.1 (2016-04-27) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 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