Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750972Ab3IFXcQ (ORCPT ); Fri, 6 Sep 2013 19:32:16 -0400 Received: from mail-yh0-f44.google.com ([209.85.213.44]:62377 "EHLO mail-yh0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750785Ab3IFXcM (ORCPT ); Fri, 6 Sep 2013 19:32:12 -0400 Date: Fri, 6 Sep 2013 17:32:05 -0600 From: Bjorn Helgaas To: Tejun Heo Cc: Alexander Gordeev , "linux-kernel@vger.kernel.org" , "x86@kernel.org" , "linux-pci@vger.kernel.org" , "linux-ide@vger.kernel.org" , Ingo Molnar , Joerg Roedel , Jan Beulich Subject: Re: [PATCH v2 2/6] PCI/MSI: Factor out pci_get_msi_cap() interface Message-ID: <20130906233205.GF12956@google.com> References: <20130905130902.GA26314@htj.dyndns.org> <20130905150259.GA30984@dhcp-26-207.brq.redhat.com> <20130905150442.GA24148@htj.dyndns.org> <20130905154041.GD30984@dhcp-26-207.brq.redhat.com> <20130905154436.GC24148@htj.dyndns.org> <20130905185440.GA13175@dhcp-26-207.brq.redhat.com> <20130905200608.GA3846@htj.dyndns.org> <20130906160621.GF22763@mtj.dyndns.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130906160621.GF22763@mtj.dyndns.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1324 Lines: 30 On Fri, Sep 06, 2013 at 12:06:21PM -0400, Tejun Heo wrote: > Hello, Bjorn. > > On Fri, Sep 06, 2013 at 10:01:38AM -0600, Bjorn Helgaas wrote: > > Sorry, I haven't jumped in here yet because I saw your discussion and > > was hoping you guys would figure something out without my help. It > > will take me a few hours to look into this and come up with anything > > constructive to say. > > > > I do remember disliking the complicated interface of > > pci_enable_msi_block() (return negative errno, return positive "we > > might be able to do this" values, or zero), but I'll have to do some > > more research before I can say much more than that. > > According to Alexander, it doesn't even seem like we have any actual > use case for the positive return numbers. I say just rip it out and > do the regular 0/-errno all the way through. I agree, that would be much simpler. I propose that you rework it that way, and at least find out what (if anything) would break if we do that. Or maybe we just give up some optimization; it would be nice to quantify that, too. Bjorn -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/