From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCH] libahci: ahci interrupt check for disabled port since private_data may be NULL Date: Thu, 17 Apr 2014 10:09:32 -0400 Message-ID: <20140417140932.GG15326@htj.dyndns.org> References: <20140415182001.GF30990@htj.dyndns.org> <20140416073919.GB2349@dhcp-26-207.brq.redhat.com> <20140416151932.GF1257@htj.dyndns.org> <20140416185105.GA21640@dhcp-26-207.brq.redhat.com> <20140416191454.GC22569@htj.dyndns.org> <20140417082934.GA30477@dhcp-26-207.brq.redhat.com> <20140417132942.GB15326@htj.dyndns.org> <20140417124436.GC2270@dhcp-26-207.brq.redhat.com> <20140417134543.GD15326@htj.dyndns.org> <20140417130732.GB2293@dhcp-26-207.brq.redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-qg0-f53.google.com ([209.85.192.53]:59979 "EHLO mail-qg0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750893AbaDQOJg (ORCPT ); Thu, 17 Apr 2014 10:09:36 -0400 Received: by mail-qg0-f53.google.com with SMTP id f51so457941qge.12 for ; Thu, 17 Apr 2014 07:09:35 -0700 (PDT) Content-Disposition: inline In-Reply-To: <20140417130732.GB2293@dhcp-26-207.brq.redhat.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Alexander Gordeev Cc: David Milburn , linux-ide@vger.kernel.org On Thu, Apr 17, 2014 at 03:07:32PM +0200, Alexander Gordeev wrote: > On Thu, Apr 17, 2014 at 09:45:43AM -0400, Tejun Heo wrote: > > > if (pp) > > > rc = devm_request_threaded_irq(..., irq + i, ...) > > > else > > > disable_irq(irq + i); > > > > Ah, was looking at the old code. But again, we didn't even request > > the irq, why would we disable it? > > The driver does not request IRQs for dummy ports, but it still requests > MSIs for them. The MSI framework initializes the resources for all MSIs > (IRQ #s, CPU interrupt vectors). Hence, although we do not request a > IRQ #, it still exists - just with no handler associated with the driver. > IOW - with a default handler, which would probably complain loudly once > an interrupt from a dummy port comes (I suppose David could check it). > > So if we just disable dummy port's IRQ #s we should never hear from them. Hmmm.... can you please prepare a proper patch with a comment explaining what's going on? I'll apply it once David verifies it. Thanks. -- tejun