From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Lezcano Subject: Re: [PATCH] ARM: OMAP4: Fix the boot regression with CPU_IDLE enabled Date: Mon, 19 May 2014 21:45:31 +0200 Message-ID: <537A5F5B.6050403@linaro.org> References: <5374FE61.50901@linaro.org> <5374FF5B.8050702@ti.com> <5375079E.3060305@ti.com> <537615EA.3020809@ti.com> <20140516212942.GK12881@atomide.com> <537A3544.1050307@linaro.org> <20140519172338.GJ4849@atomide.com> <537A408F.7070301@ti.com> <20140519175157.GK4849@atomide.com> <537A4827.30604@linaro.org> <20140519193622.GA11945@atomide.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mail-we0-f181.google.com ([74.125.82.181]:61278 "EHLO mail-we0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932702AbaESTpU (ORCPT ); Mon, 19 May 2014 15:45:20 -0400 Received: by mail-we0-f181.google.com with SMTP id w61so5909787wes.40 for ; Mon, 19 May 2014 12:45:18 -0700 (PDT) In-Reply-To: <20140519193622.GA11945@atomide.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Tony Lindgren Cc: Santosh Shilimkar , Alex Shi , khilman@linaro.org, linux-arm-kernel@lists.infradead.org, linux-omap@vger.kernel.org, Roger Quadros , Tobias Jakobi On 05/19/2014 09:36 PM, Tony Lindgren wrote: > * Daniel Lezcano [140519 11:07]: >> On 05/19/2014 07:51 PM, Tony Lindgren wrote: >>> * Santosh Shilimkar [140519 10:35]: >>>> On Monday 19 May 2014 01:23 PM, Tony Lindgren wrote: >>>>> * Daniel Lezcano [140519 09:46]: >>>>>> On 05/16/2014 11:29 PM, Tony Lindgren wrote: >>>>>>> >>>>>>> And just to recap, this problem can be reproduced with current >>>>>>> Linux next with omap2plus_defconfig with CONFIG_CPU_IDLE enable= d. The >>>>>>> system should hang during the boot at some point. >>>>>> >>>>>> I can take the time to investigate a bit more but not right now.= What is >>>>>> your deadline before committing the reverts ? >>>>> >>>>> Well we do have several automated build and boot systems failing >>>>> because of this with multi_v7_defconfig. And users are complainin= g, >>>>> see this report from Tobias Jakobi: >>>>> >>>>> https://bugzilla.kernel.org/show_bug.cgi?id=3D75421 >>>>> >>>>> It seems that doing the revert is not enough based on the >>>>> page above. >>>>> >>>> Thats not true. The above link used the half patch and not the >>>> updated patch. Updated patch worked for Alex also. As you can >>>> see they saw RCU stalls and they go away after the updated patch. >>>> >>>> Can you please point them to try out the updated patch ? >>> >>> OK good point. I added a link to the updated patch in >>> bugzilla. >>> >>>>> I'd prefer we'd fix this issue properly for sure, it seems that >>>>> we're not quite understanding what's going on. And this might >>>>> hit other platforms too when they start implementing deeper >>>>> PM idle states in the mainline kernel. >>>>> >>>> I am certain that the updated patch fixed the regression >>>> for sure. The issue is really not generic enough since its related >>>> an OMAP ROM errata which needs that special handling of >>>> interrupt re-trigger etc. You don't need that for other platforms >>>> so they are not likely get affected. >>> >>> OK makes sense to me considering the ROM code. Daniel, are you OK >>> with that or do you still want to investigate further? >> >> For the moment I am a bit short in time for some other tasks. So fee= l free >> to apply the revert and I will look for a proper fix when I will hav= e time. > > Added Tobias to Cc. At the bugzilla link Tobias is saying > he used the right patch from Santosh to test and it still > fails. So apparently Santosh, Kevin and Alex say they are not facing the issue= =20 anymore with the revert. But Tobias is still facing this issue. There is this simple program [1] which usually makes cpuidle to hang th= e=20 system more quickly when there is a problem somewhere. May be worth to=20 check with it. Hope that helps. -- Daniel [1]=20 https://git.linaro.org/power/pm-qa.git/blob/HEAD:/cpuidle/cpuidle_kille= r.c --=20 Linaro.org =E2=94=82 Open source software fo= r ARM SoCs =46ollow Linaro: Facebook | Twitter | Blog -- To unsubscribe from this list: send the line "unsubscribe linux-omap" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html From mboxrd@z Thu Jan 1 00:00:00 1970 From: daniel.lezcano@linaro.org (Daniel Lezcano) Date: Mon, 19 May 2014 21:45:31 +0200 Subject: [PATCH] ARM: OMAP4: Fix the boot regression with CPU_IDLE enabled In-Reply-To: <20140519193622.GA11945@atomide.com> References: <5374FE61.50901@linaro.org> <5374FF5B.8050702@ti.com> <5375079E.3060305@ti.com> <537615EA.3020809@ti.com> <20140516212942.GK12881@atomide.com> <537A3544.1050307@linaro.org> <20140519172338.GJ4849@atomide.com> <537A408F.7070301@ti.com> <20140519175157.GK4849@atomide.com> <537A4827.30604@linaro.org> <20140519193622.GA11945@atomide.com> Message-ID: <537A5F5B.6050403@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 05/19/2014 09:36 PM, Tony Lindgren wrote: > * Daniel Lezcano [140519 11:07]: >> On 05/19/2014 07:51 PM, Tony Lindgren wrote: >>> * Santosh Shilimkar [140519 10:35]: >>>> On Monday 19 May 2014 01:23 PM, Tony Lindgren wrote: >>>>> * Daniel Lezcano [140519 09:46]: >>>>>> On 05/16/2014 11:29 PM, Tony Lindgren wrote: >>>>>>> >>>>>>> And just to recap, this problem can be reproduced with current >>>>>>> Linux next with omap2plus_defconfig with CONFIG_CPU_IDLE enabled. The >>>>>>> system should hang during the boot at some point. >>>>>> >>>>>> I can take the time to investigate a bit more but not right now. What is >>>>>> your deadline before committing the reverts ? >>>>> >>>>> Well we do have several automated build and boot systems failing >>>>> because of this with multi_v7_defconfig. And users are complaining, >>>>> see this report from Tobias Jakobi: >>>>> >>>>> https://bugzilla.kernel.org/show_bug.cgi?id=75421 >>>>> >>>>> It seems that doing the revert is not enough based on the >>>>> page above. >>>>> >>>> Thats not true. The above link used the half patch and not the >>>> updated patch. Updated patch worked for Alex also. As you can >>>> see they saw RCU stalls and they go away after the updated patch. >>>> >>>> Can you please point them to try out the updated patch ? >>> >>> OK good point. I added a link to the updated patch in >>> bugzilla. >>> >>>>> I'd prefer we'd fix this issue properly for sure, it seems that >>>>> we're not quite understanding what's going on. And this might >>>>> hit other platforms too when they start implementing deeper >>>>> PM idle states in the mainline kernel. >>>>> >>>> I am certain that the updated patch fixed the regression >>>> for sure. The issue is really not generic enough since its related >>>> an OMAP ROM errata which needs that special handling of >>>> interrupt re-trigger etc. You don't need that for other platforms >>>> so they are not likely get affected. >>> >>> OK makes sense to me considering the ROM code. Daniel, are you OK >>> with that or do you still want to investigate further? >> >> For the moment I am a bit short in time for some other tasks. So feel free >> to apply the revert and I will look for a proper fix when I will have time. > > Added Tobias to Cc. At the bugzilla link Tobias is saying > he used the right patch from Santosh to test and it still > fails. So apparently Santosh, Kevin and Alex say they are not facing the issue anymore with the revert. But Tobias is still facing this issue. There is this simple program [1] which usually makes cpuidle to hang the system more quickly when there is a problem somewhere. May be worth to check with it. Hope that helps. -- Daniel [1] https://git.linaro.org/power/pm-qa.git/blob/HEAD:/cpuidle/cpuidle_killer.c -- Linaro.org ? Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog