Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756294AbcCaNmC (ORCPT ); Thu, 31 Mar 2016 09:42:02 -0400 Received: from mailgw01.mediatek.com ([210.61.82.183]:5274 "EHLO mailgw01.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1750762AbcCaNmA (ORCPT ); Thu, 31 Mar 2016 09:42:00 -0400 Message-ID: <1459431711.395.6.camel@mtksdaap41> Subject: Re: [PATCH] mfd: mt6397: irq domain should initialize before mfd_add_devices() From: Yingjoe Chen To: John Crispin CC: Henry Chen , Sascha Hauer , , Flora Fu , , "Matthias Brugger" , Lee Jones , , Date: Thu, 31 Mar 2016 21:41:51 +0800 In-Reply-To: <56FCE910.8030100@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> 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: 2853 Lines: 87 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