Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965712AbcCNPwX (ORCPT ); Mon, 14 Mar 2016 11:52:23 -0400 Received: from mail.kernel.org ([198.145.29.136]:40076 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754286AbcCNPwU (ORCPT ); Mon, 14 Mar 2016 11:52:20 -0400 Date: Mon, 14 Mar 2016 10:52:12 -0500 From: Bjorn Helgaas To: Adrian Hunter Cc: "Rafael J. Wysocki" , Alexandre Courbot , linux-pci@vger.kernel.org, Bjorn Helgaas , Alexandre Courbot , Ulf Hansson , Arnd Bergmann , linux-mmc , Linux Kernel Mailing List Subject: Re: [PATCH v4 3/3] mmc: sdhci-pci: Do not set DMA mask in enable_dma() Message-ID: <20160314155211.GC13471@localhost> References: <1457316477-8153-1-git-send-email-acourbot@nvidia.com> <1457316477-8153-4-git-send-email-acourbot@nvidia.com> <56DED13E.9060106@intel.com> <56E6B5F4.6090602@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <56E6B5F4.6090602@intel.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: 1622 Lines: 38 On Mon, Mar 14, 2016 at 03:00:36PM +0200, Adrian Hunter wrote: > On 14/03/16 05:15, Alexandre Courbot wrote: > > On Tue, Mar 8, 2016 at 10:18 PM, Adrian Hunter wrote: > >> On 07/03/16 04:07, Alexandre Courbot wrote: > >>> DMA mask will already be set by sdhci_set_dma_mask(), which > >>> is equivalent to the removed code since pci_set_dma_mask() > >>> expands to its DMA-API counterpart. > >>> > >>> There should also be no reason to set the DMA mask after probe. > >> > >> Let's run that by the PCI mailing list just to be sure. The patches for > >> reference: > >> > >> http://marc.info/?l=linux-mmc&m=145731654328126&w=2 > >> http://marc.info/?l=linux-mmc&m=145731654328128&w=2 > >> > >> change the sdhci-pci driver to set the DMA mask once during probe instead of > >> every time during resume. Is there any reason a PCI device driver might > >> need to set the DMA mask every time during resume? > > > > Not seeing much reaction for this patchset. PCI being the only > > possible point of contention, can we maybe roll it into -next and see > > what happens? > > +Rafael > > Rafael, can you offer any thoughts on this: > > PCI drivers that want to use DMA might call pci_set_master() in the pm > resume callback. Some drivers (like sdhci-pci) also, presumably out of > convenience, set the DMA mask at the same time. The question is: is it OK > instead to set the DMA mask just once during probe, or is there some other > reason the DMA mask needs to be set every time during resume? I don't see a reason why the DMA mask would need to be set during resume. Bjorn