Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754179AbbHaS7V (ORCPT ); Mon, 31 Aug 2015 14:59:21 -0400 Received: from mail-ob0-f172.google.com ([209.85.214.172]:33897 "EHLO mail-ob0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754156AbbHaS7S (ORCPT ); Mon, 31 Aug 2015 14:59:18 -0400 MIME-Version: 1.0 In-Reply-To: <69e6f5bf693d02fba001d02047453bed0519499d.1440098398.git.dhdang@apm.com> References: <1522889.9kdnRk8vHo@wuerfel> <69e6f5bf693d02fba001d02047453bed0519499d.1440098398.git.dhdang@apm.com> From: Duc Dang Date: Mon, 31 Aug 2015 11:58:48 -0700 Message-ID: Subject: Re: [PATCH v7 1/2] usb: make xhci platform driver use 64 bit or 32 bit DMA To: Greg KH , Russell King - ARM Linux , Loc Ho , Arnd Bergmann Cc: USB list , linux-arm , Linux Kernel Mailing List , mathias.nyman@intel.com, Mark Langsdorf , patches , Feng Kan , Duc Dang 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: 2974 Lines: 86 On Thu, Aug 20, 2015 at 12:38 PM, Duc Dang wrote: > The xhci platform driver needs to work on systems that > either only support 64-bit DMA or only support 32-bit DMA. > Attempt to set a coherent dma mask for 64-bit DMA, and > attempt again with 32-bit DMA if that fails. > > [dhdang: regenerate the patch over 4.2-rc5 and address new comments] > Signed-off-by: Mark Langsdorf > Tested-by: Mark Salter > Signed-off-by: Duc Dang > > --- > Changes from v6: > -Add WARN_ON if dma_mask is NULL > -Use dma_coerce_mask_and_coherent to assign > dma_mask and coherent_dma_mask > > Changes from v5: > -Change comment > -Assign dma_mask to coherent_dma_mask if dma_mask is NULL > to make sure dma_set_mask_and_coherent does not fail prematurely. > > Changes from v4: > -None > > Changes from v3: > -Re-generate the patch over 4.2-rc5 > -No code change. > > Changes from v2: > -None > > Changes from v1: > -Consolidated to use dma_set_mask_and_coherent > -Got rid of the check against sizeof(dma_addr_t) > > drivers/usb/host/xhci-plat.c | 21 +++++++++++++-------- > 1 file changed, 13 insertions(+), 8 deletions(-) > > diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c > index 890ad9d..e4c7f9d 100644 > --- a/drivers/usb/host/xhci-plat.c > +++ b/drivers/usb/host/xhci-plat.c > @@ -93,14 +93,19 @@ static int xhci_plat_probe(struct platform_device *pdev) > if (irq < 0) > return -ENODEV; > > - /* Initialize dma_mask and coherent_dma_mask to 32-bits */ > - ret = dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(32)); > - if (ret) > - return ret; > - if (!pdev->dev.dma_mask) > - pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask; > - else > - dma_set_mask(&pdev->dev, DMA_BIT_MASK(32)); > + /* Throw a waring if broken platform code didn't initialize dma_mask */ > + WARN_ON(!pdev->dev.dma_mask); > + /* > + * Try setting dma_mask and coherent_dma_mask to 64 bits, > + * then try 32 bits > + */ > + ret = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64)); > + if (ret) { > + ret = dma_coerce_mask_and_coherent(&pdev->dev, > + DMA_BIT_MASK(32)); > + if (ret) > + return ret; > + } > > hcd = usb_create_hcd(driver, &pdev->dev, dev_name(&pdev->dev)); > if (!hcd) > -- > 1.9.1 > Hi Greg, Arnd, Russell, Do you have any more comment about this patch set? -- Duc Dang. -- 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/