Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Message-ID: <1516908343.5161.4.camel@redhat.com>
Subject: Re: "irq/matrix: Spread interrupts on allocation" breaks nouveau in
 mainline kernel
From:   Lyude Paul <lyude@redhat.com>
Reply-To: lyude@redhat.com
To:     Thomas Gleixner <tglx@linutronix.de>
Cc:     "Ghannam, Yazen" <Yazen.Ghannam@amd.com>,
        "hpa@zytor.com" <hpa@zytor.com>,
        "keith.busch@intel.com" <keith.busch@intel.com>,
        "mingo@kernel.org" <mingo@kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Borislav Petkov <bp@alien8.de>
Date:   Thu, 25 Jan 2018 14:25:43 -0500
In-Reply-To: <alpine.DEB.2.20.1801251945170.2203@nanos>
References: <1516744873.29151.3.camel@redhat.com>
           <1516757219.29151.7.camel@redhat.com>
           <alpine.DEB.2.20.1801241351080.1997@nanos>
           <1516816150.4109.2.camel@redhat.com>
           <DM5PR12MB19161E66F534B7050B8CCBF0F8E20@DM5PR12MB1916.namprd12.prod.outlook.com>
         <1516823810.4109.26.camel@redhat.com>
          <alpine.DEB.2.20.1801250945080.2020@nanos>
         <1516904638.5161.1.camel@redhat.com>
         <alpine.DEB.2.20.1801251945170.2203@nanos>
Organization: Red Hat
Content-Type: text/plain; charset="UTF-8"
Mime-Version: 1.0
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Thu, 2018-01-25 at 19:46 +0100, Thomas Gleixner wrote:
> On Thu, 25 Jan 2018, Lyude Paul wrote:
> 
> > I think you are right, apologies. Glad to know this isn't a regression in
> > the
> > IRQ handling code :). It looks like our nouveau problems are probably coming
> > from the fact that we don't just leave IRQs setup through suspend/resume
> > which
> > as far as I can tell, is probably not the correct thing to do.
> 
> If you tear down the interrupt, then you have to make sure that it's
> completely masked and disabled on the device side (including MSI).
Does this only need to be done if we handle irq_request()/irq_free() ourselves,
or can we skip some of these steps if we let the kernel handle
disabling/enabling IRQs during s/r?
> 
> Thanks,
> 
> 	tglx