Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760073Ab3ICOSa (ORCPT ); Tue, 3 Sep 2013 10:18:30 -0400 Received: from mail-ye0-f182.google.com ([209.85.213.182]:56466 "EHLO mail-ye0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753542Ab3ICOS2 (ORCPT ); Tue, 3 Sep 2013 10:18:28 -0400 Date: Tue, 3 Sep 2013 10:18:24 -0400 From: Tejun Heo To: Alexander Gordeev Cc: linux-kernel@vger.kernel.org, x86@kernel.org, linux-pci@vger.kernel.org, linux-ide@vger.kernel.org, Ingo Molnar , Joerg Roedel , Jan Beulich , Bjorn Helgaas Subject: Re: [PATCH 3/4] AHCI: Conserve interrupts with pci_enable_msi_block_part() interface Message-ID: <20130903141824.GD10522@htj.dyndns.org> References: <3bb1b4375655ecfde5017cc70973d078f2434d5d.1378111919.git.agordeev@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3bb1b4375655ecfde5017cc70973d078f2434d5d.1378111919.git.agordeev@redhat.com> 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: 841 Lines: 30 On Mon, Sep 02, 2013 at 11:00:28AM +0200, Alexander Gordeev wrote: > + if (hpriv->flags & AHCI_HFLAG_NO_MSI) > + goto intx; > + > + rc = pci_enable_msi_block_part(pdev, n_ports, AHCI_MAX_PORTS); > + if (!rc) > + return AHCI_MAX_PORTS; > + if (rc < 0) > + goto intx; > + > + maxvec = rc; > + rc = pci_enable_msi_block_part(pdev, n_ports, maxvec); > + if (!rc) > + return maxvec; > + if (rc < 0) > + goto intx; Why is the above fallback necessary? The only other number which makes sense is roundup_pow_of_two(n_ports), right? What does the above fallback logic buy us? Thanks. -- tejun -- 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/