Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965256AbcCNNEU (ORCPT ); Mon, 14 Mar 2016 09:04:20 -0400 Received: from mga11.intel.com ([192.55.52.93]:18323 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964960AbcCNNEP (ORCPT ); Mon, 14 Mar 2016 09:04:15 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.24,335,1455004800"; d="scan'208";a="909879667" Subject: Re: [PATCH v4 3/3] mmc: sdhci-pci: Do not set DMA mask in enable_dma() To: "Rafael J. Wysocki" References: <1457316477-8153-1-git-send-email-acourbot@nvidia.com> <1457316477-8153-4-git-send-email-acourbot@nvidia.com> <56DED13E.9060106@intel.com> Cc: Alexandre Courbot , linux-pci@vger.kernel.org, Bjorn Helgaas , Alexandre Courbot , Ulf Hansson , Arnd Bergmann , linux-mmc , Linux Kernel Mailing List From: Adrian Hunter Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki Message-ID: <56E6B5F4.6090602@intel.com> Date: Mon, 14 Mar 2016 15:00:36 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.5.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1413 Lines: 32 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?