Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751953AbcCGCGf (ORCPT ); Sun, 6 Mar 2016 21:06:35 -0500 Received: from mail-ig0-f182.google.com ([209.85.213.182]:37006 "EHLO mail-ig0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751341AbcCGCG0 (ORCPT ); Sun, 6 Mar 2016 21:06:26 -0500 MIME-Version: 1.0 In-Reply-To: <2562091.6cJRuD3dK9@wuerfel> References: <1457087925-992-1-git-send-email-acourbot@nvidia.com> <1457087925-992-2-git-send-email-acourbot@nvidia.com> <2562091.6cJRuD3dK9@wuerfel> From: Alexandre Courbot Date: Mon, 7 Mar 2016 11:06:06 +0900 Message-ID: Subject: Re: [PATCH v3 1/3] mmc: sdhci: Set DMA mask when adding host To: Arnd Bergmann Cc: Alexandre Courbot , Ulf Hansson , Adrian Hunter , linux-mmc , Linux Kernel Mailing List Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1773 Lines: 44 On Sat, Mar 5, 2016 at 12:57 AM, Arnd Bergmann wrote: > On Friday 04 March 2016 19:38:43 Alexandre Courbot wrote: >> Set the DMA mask in sdhci_add_host() after we determined the >> capabilities of the device. 64-bit devices in particular are given the >> proper mask that ensures bounce buffers are not used. >> >> Also disable DMA if no proper DMA mask can be set, as the DMA-API >> documentation specifies. >> >> Signed-off-by: Alexandre Courbot >> --- >> drivers/mmc/host/sdhci.c | 46 +++++++++++++++++++++++++++++++++++++++------- >> 1 file changed, 39 insertions(+), 7 deletions(-) >> >> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c >> index fd9139947fa3..00fb45ba6f39 100644 >> --- a/drivers/mmc/host/sdhci.c >> +++ b/drivers/mmc/host/sdhci.c >> @@ -2857,6 +2857,34 @@ struct sdhci_host *sdhci_alloc_host(struct device *dev, >> >> EXPORT_SYMBOL_GPL(sdhci_alloc_host); >> >> +static int sdhci_set_dma_mask(struct sdhci_host *host) >> +{ >> + struct mmc_host *mmc = host->mmc; >> + struct device *dev = mmc_dev(mmc); >> + int ret = -EINVAL; >> + >> + if (host->quirks2 & SDHCI_QUIRK2_BROKEN_64_BIT_DMA) >> + host->flags &= ~SDHCI_USE_64_BIT_DMA; >> + >> + /* Try 64-bit mask if hardware is capable of it */ >> + if (host->flags & SDHCI_USE_64_BIT_DMA) { >> + ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64)); >> + if (ret) >> + pr_warn("%s: Failed to set 64-bit DMA mask.\n", >> + mmc_hostname(mmc)); >> + } >> + > > I think you need to disable the SDHCI_USE_64_BIT_DMA flag when > dma_set_mask_and_coherent() fails here. Otherwise looks good. Ah, you're right, thanks. v4 is on the way.