From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexander Gordeev Subject: Re: [PATCH] libahci: ahci interrupt check for disabled port since private_data may be NULL Date: Thu, 17 Apr 2014 15:07:32 +0200 Message-ID: <20140417130732.GB2293@dhcp-26-207.brq.redhat.com> References: <20140415181812.GA11614@dhcp-10-15-1-70.hsv.redhat.com> <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> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mx1.redhat.com ([209.132.183.28]:45077 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750928AbaDQOFt (ORCPT ); Thu, 17 Apr 2014 10:05:49 -0400 Content-Disposition: inline In-Reply-To: <20140417134543.GD15326@htj.dyndns.org> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Tejun Heo Cc: David Milburn , linux-ide@vger.kernel.org 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. > Thanks. > > -- > tejun -- Regards, Alexander Gordeev agordeev@redhat.com