Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755020Ab3JBRXm (ORCPT ); Wed, 2 Oct 2013 13:23:42 -0400 Received: from userp1040.oracle.com ([156.151.31.81]:49789 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754248Ab3JBRXl (ORCPT ); Wed, 2 Oct 2013 13:23:41 -0400 Date: Wed, 2 Oct 2013 13:22:58 -0400 From: Konrad Rzeszutek Wilk To: Stefano Stabellini Cc: xen-devel@lists.xensource.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Ian Campbell , rob.herring@calxeda.com Subject: Re: [PATCH v6 15/19] swiotlb-xen: call dma_capable only if dev->dma_mask is allocated Message-ID: <20131002172258.GC24791@phenom.dumpdata.com> References: <1380298207-29151-15-git-send-email-stefano.stabellini@eu.citrix.com> <20130930160223.GU3106@phenom.dumpdata.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) X-Source-IP: ucsinet22.oracle.com [156.151.31.94] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2909 Lines: 71 On Wed, Oct 02, 2013 at 06:13:35PM +0100, Stefano Stabellini wrote: > The real issue is that some devices (xgmac, I am looking at you), don't > set the dma_mask, even though they are perfectly capable of doing dma. So this looks like a bug in the drivers. I thought I saw a huge patchset by the ARM maintainer that tries to fix the dma_mask and dma_mask_coherent bugs? And also fix the drivers to use the dma mask? > > Maybe I should modify the arm implementation of dma_capable (see > http://marc.info/?l=linux-kernel&m=138029832007821&w=2) to ignore the > dma_mask. Or fix the 'xgmac'? > > On Mon, 30 Sep 2013, Konrad Rzeszutek Wilk wrote: > > On Fri, Sep 27, 2013 at 05:10:03PM +0100, Stefano Stabellini wrote: > > > > Why? I am looking at X86 and IA64 and I see: > > > > 79 if (!dev->dma_mask) > > 80 return 0; > > > > > > Why not port dma_capable over to ARM? > > > > > Signed-off-by: Stefano Stabellini > > > --- > > > drivers/xen/swiotlb-xen.c | 6 +++--- > > > 1 files changed, 3 insertions(+), 3 deletions(-) > > > > > > diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c > > > index 790c2eb..3011736 100644 > > > --- a/drivers/xen/swiotlb-xen.c > > > +++ b/drivers/xen/swiotlb-xen.c > > > @@ -512,7 +512,7 @@ dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page, > > > * buffering it. > > > */ > > > if (!xen_feature(XENFEAT_auto_translated_physmap) && > > > - dma_capable(dev, dev_addr, size) && > > > + dev->dma_mask && dma_capable(dev, dev_addr, size) && > > > !range_straddles_page_boundary(phys, size) && !swiotlb_force) > > > return dev_addr; > > > > > > @@ -532,7 +532,7 @@ dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page, > > > /* > > > * Ensure that the address returned is DMA'ble > > > */ > > > - if (!dma_capable(dev, dev_addr, size)) { > > > + if (dev->dma_mask && !dma_capable(dev, dev_addr, size)) { > > > swiotlb_tbl_unmap_single(dev, map, size, dir); > > > dev_addr = 0; > > > } > > > @@ -660,7 +660,7 @@ xen_swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, > > > > > > if (swiotlb_force || > > > xen_feature(XENFEAT_auto_translated_physmap) || > > > - !dma_capable(hwdev, dev_addr, sg->length) || > > > + (hwdev->dma_mask && !dma_capable(hwdev, dev_addr, sg->length)) || > > > range_straddles_page_boundary(paddr, sg->length)) { > > > /* > > > * Pass the dma_addr of the first slab in the iotlb buffer as > > > -- > > > 1.7.2.5 > > > > > -- 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/