Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933275AbcDFCrx (ORCPT ); Tue, 5 Apr 2016 22:47:53 -0400 Received: from mailgw02.mediatek.com ([210.61.82.184]:61182 "EHLO mailgw02.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1753145AbcDFCrw (ORCPT ); Tue, 5 Apr 2016 22:47:52 -0400 Message-ID: <1459910866.18284.27.camel@mtksdaap41> Subject: Re: [PATCH] mfd: mt6397: irq domain should initialize before mfd_add_devices() From: Henry Chen To: John Crispin CC: Yingjoe Chen , Sascha Hauer , , Flora Fu , , , Matthias Brugger , Lee Jones , Date: Wed, 6 Apr 2016 10:47:46 +0800 In-Reply-To: <56FD2F18.4050508@openwrt.org> References: <1459322708-21363-1-git-send-email-henryc.chen@mediatek.com> <56FB99DB.6010901@openwrt.org> <1459388452.18284.2.camel@mtksdaap41> <1459391533.21870.15.camel@mtksdaap41> <56FCE910.8030100@openwrt.org> <1459431711.395.6.camel@mtksdaap41> <56FD2F18.4050508@openwrt.org> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3-0ubuntu6 Content-Transfer-Encoding: 7bit MIME-Version: 1.0 X-MTK: N Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3517 Lines: 108 On Thu, 2016-03-31 at 16:07 +0200, John Crispin wrote: > > On 31/03/2016 15:41, Yingjoe Chen wrote: > > On Thu, 2016-03-31 at 11:08 +0200, John Crispin wrote: > >> > >> On 31/03/2016 04:32, Yingjoe Chen wrote: > >>> On Thu, 2016-03-31 at 09:40 +0800, Henry Chen wrote: > >>>> On Wed, 2016-03-30 at 11:18 +0200, John Crispin wrote: > >>>>> Hi, > >>>>> > >>>>> small nitpick inline > >>>>> > >>>>> On 30/03/2016 09:25, Henry Chen wrote: > >>>>>> Some sub driver like RTC module need irq domain from parent to create > >>>>>> irq mapping when driver initialize. so move mt6397_irq_init() before > >>>>>> mfd_add_devices(). > >>>>>> > >>>>>> Signed-off-by: Henry Chen > >>>>>> --- > >>>>>> This patch fixed the below warning based on "Linux kernel v4.6-rc1" > >>>>>> WARNING: CPU: 1 PID: 132 at kernel/mediatek/kernel/irq/irqdomain.c:471 > >>>>>> irq_create_mapping+0xc4/0xd0 > >>>>>> --- > >>>>>> drivers/mfd/mt6397-core.c | 37 ++++++++++++++++++++++--------------- > >>>>>> 1 file changed, 22 insertions(+), 15 deletions(-) > >>>>>> > >>>>>> diff --git a/drivers/mfd/mt6397-core.c b/drivers/mfd/mt6397-core.c > >>>>>> index 8e8d932..a879223 100644 > >>>>>> --- a/drivers/mfd/mt6397-core.c > >>>>>> +++ b/drivers/mfd/mt6397-core.c > >>>>>> @@ -270,22 +270,36 @@ static int mt6397_probe(struct platform_device *pdev) > >>>>>> goto fail_irq; > >>>>>> } > >>>>>> > >>>>>> + pmic->irq = platform_get_irq(pdev, 0); > >>>>>> + > >>>>>> switch (id & 0xff) { > >>>>>> case MT6323_CID_CODE: > >>>>>> - pmic->int_con[0] = MT6323_INT_CON0; > >>>>>> - pmic->int_con[1] = MT6323_INT_CON1; > >>>>>> - pmic->int_status[0] = MT6323_INT_STATUS0; > >>>>>> - pmic->int_status[1] = MT6323_INT_STATUS1; > >>>>>> + if (pmic->irq > 0) { > >>>>> > >>>>> should this not be > >>>>> > >>>>> if (pmic->irq >= 0) { > >>>>> > >>>>> i think the code before your patch was wrong as linux irqs start with 0. > >>>>> > >>>>> John > >>>> Hi John, > >>>> > >>>> Thanks, I will modify this. > >>> > >>> Linux irq start from 1, 0 is invalid. I can't find the document saying > >>> this now, but you could see this from irq_create_mapping() in > >>> kernel/irq/irqdomain.c > >>> > >>> I think the code should have check return from platform_get_irq and > >>> handle -EPROBE_DEFER, but maybe it should be another patch? > >>> > >>> BTW, in this function, it is possible that pmic->irq_domain will be NULL > >>> in fail_irq error handling. We should check before calling > >>> irq_domain_remove. > >>> > >>> Joe.C > >>> > >> > >> Hi, > >> > >> looking at > >> http://lxr.free-electrons.com/source/drivers/base/platform.c#L87 there > >> is a check in line #100 ret >= 0 > >> > >> checking the return value of pmic->irq = platform_get_irq(pdev, 0); > >> should follow the same pattern i think .. unless i have a thinko and am > >> reading the code wrong. > > > > > > I'm not sure why platform_get_irq() check for 0, but I think the code > > logic is differnet. > > > > When platform_get_irq() return 0 to our code, it means we don't have > > valid irq to use. In this case it doesn't make any sense to continue > > init irq. > > > > > > Joe.C > > > > > --> http://lwn.net/Articles/470820/ > > indeed ARM has changed this is seems. was not aware of this change, > sorry for the noise > > John Hi Lee/Joe/John, Thanks for comment, that means we can keep this patch for 4.6-rc1 regression (RTC get NULL irq issue), right? I will send another patch to fixed above error handling problem. Thanks. Henry